diff --git a/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/time.html.twig b/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/time.html.twig
index 2738ddb14c..9515272f7b 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/time.html.twig
+++ b/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/time.html.twig
@@ -48,7 +48,7 @@
             </tr>
             <tr>
                 <th>Threshold</th>
-                <td><input type="number" size="3" name="threshold" value="{{ threshold }}" /> ms</td>
+                <td><input type="number" size="3" name="threshold" value="{{ threshold }}" min="0" /> ms</td>
             </tr>
             <tr>
                 <th>Width</th>
@@ -87,174 +87,153 @@
         {% endfor %}
     {% endif %}
 
-    <script type="text/javascript">
+    <script type="text/javascript">//<![CDATA[
         function drawCanvas(request, max, threshold, width) {
-            var colors = {
-                {% for name, color in colors %}
-                    "{{ name }}": "{{ color }}"{{ loop.last ? '' : ', ' }}
-                {% endfor %}
-            };
-            var space = 10.5;
-            var ratio = (width - space * 2) / max;
-            var height = 0;
-            for (i = 0; i < request.events.length; i++) {
-                if (request.events[i].totaltime < threshold) {
-                    continue;
-                }
+            "use strict";
+            var text,
+                ms,
+                xc,
+                mainEvents,
+                colors = {{ colors|json_encode|raw }},
+                space = 10.5,
+                ratio = (width - space * 2) / max,
+                height = 0,
+                h = space,
+                x = request.left * ratio + space,
+                canvas = document.getElementById('timeline_' + request.id),
+                ctx = canvas.getContext("2d");
 
-                height = height + 38;
-            }
-            var h = space;
-            var x = request.left * ratio + space;
+            request.events = request.events.filter(function(event) {
+                return event.totaltime >= threshold;
+            });
 
-            var canvas = document.getElementById('timeline_' + request.id);
+            height += 38 * request.events.length;
             canvas.width = width;
+            ctx.textBaseline = "middle";
+            ctx.lineWidth = 0;
 
-            var context = canvas.getContext("2d");
-            context.textBaseline = "middle";
-            context.lineWidth = 0;
-
-            for (i = 0; i < request.events.length; i++) {
-                var event = request.events[i];
-
-                if (event.totaltime < threshold) {
-                    continue;
-                }
-
-                for (j = 0; j < event.periods.length; j++) {
-                    var period = event.periods[j];
-
-                    if ('section.child' == event.name) {
-                        context.fillStyle = colors.child_sections;
-                        context.fillRect(x + period.begin * ratio, 0, (period.end - period.begin) * ratio, height);
-                    } else if ('section' == event.category) {
-                        context.beginPath();
-                        context.strokeStyle = "#dfdfdf";
-                        context.moveTo(x + period.begin * ratio, 0);
-                        context.lineTo(x + period.begin * ratio, height);
-                        context.moveTo(x + period.end * ratio, 0);
-                        context.lineTo(x + period.end * ratio, height);
-                        context.fill();
-                        context.closePath();
-                        context.stroke();
+            request.events.forEach(function(event) {
+                event.periods.forEach(function(period) {
+                    if ('section.child' === event.name) {
+                        ctx.fillStyle = colors.child_sections;
+                        ctx.fillRect(x + period.begin * ratio, 0, (period.end - period.begin) * ratio, height);
+                    } else if ('section' === event.category) {
+                        ctx.beginPath();
+                        ctx.strokeStyle = "#dfdfdf";
+                        ctx.moveTo(x + period.begin * ratio, 0);
+                        ctx.lineTo(x + period.begin * ratio, height);
+                        ctx.moveTo(x + period.end * ratio, 0);
+                        ctx.lineTo(x + period.end * ratio, height);
+                        ctx.fill();
+                        ctx.closePath();
+                        ctx.stroke();
                     }
-                }
-            }
+                });
+            });
 
-            for (i = 0; i < request.events.length; i++) {
-                var event = request.events[i];
+            mainEvents = request.events.filter(function(event) {
+                return 'section.child' !== event.name;
+            });
 
-                if (event.totaltime < threshold || 'section.child' == event.name) {
-                    continue;
-                }
+            mainEvents.forEach(function(event) {
 
                 h += 8;
 
-                for (j = 0; j < event.periods.length; j++) {
-                    var period = event.periods[j];
+                event.periods.forEach(function(period) {
 
                     if (colors[event.name]) {
-                        context.fillStyle = colors[event.name];
-                        context.strokeStyle = colors[event.name];
+                        ctx.fillStyle = colors[event.name];
+                        ctx.strokeStyle = colors[event.name];
                     } else if (colors[event.category]) {
-                        context.fillStyle = colors[event.category];
-                        context.strokeStyle = colors[event.category];
+                        ctx.fillStyle = colors[event.category];
+                        ctx.strokeStyle = colors[event.category];
                     } else {
-                        context.fillStyle = colors.default;
-                        context.strokeStyle = colors.default;
+                        ctx.fillStyle = colors['default'];
+                        ctx.strokeStyle = colors['default'];
                     }
 
-                    if ('section' != event.category) {
-                        context.fillRect(x + period.begin * ratio, h + 3, 2, 6);
-                        context.fillRect(x + period.begin * ratio, h, (period.end - period.begin) * ratio ? (period.end - period.begin) * ratio : 2, 6);
+                    if ('section' !== event.category) {
+                        ctx.fillRect(x + period.begin * ratio, h + 3, 2, 6);
+                        ctx.fillRect(x + period.begin * ratio, h, (period.end - period.begin) * ratio || 2, 6);
                     } else {
-                        context.beginPath();
-                        context.moveTo(x + period.begin * ratio, h);
-                        context.lineTo(x + period.begin * ratio, h + 11);
-                        context.lineTo(x + period.begin * ratio + 8, h);
-                        context.lineTo(x + period.begin * ratio, h);
-                        context.fill();
-                        context.closePath();
-                        context.stroke();
+                        ctx.beginPath();
+                        ctx.moveTo(x + period.begin * ratio, h);
+                        ctx.lineTo(x + period.begin * ratio, h + 11);
+                        ctx.lineTo(x + period.begin * ratio + 8, h);
+                        ctx.lineTo(x + period.begin * ratio, h);
+                        ctx.fill();
+                        ctx.closePath();
+                        ctx.stroke();
 
-                        context.beginPath();
-                        context.moveTo(x + period.end * ratio, h);
-                        context.lineTo(x + period.end * ratio, h + 11);
-                        context.lineTo(x + period.end * ratio - 8, h);
-                        context.lineTo(x + period.end * ratio, h);
-                        context.fill();
-                        context.closePath();
-                        context.stroke();
+                        ctx.beginPath();
+                        ctx.moveTo(x + period.end * ratio, h);
+                        ctx.lineTo(x + period.end * ratio, h + 11);
+                        ctx.lineTo(x + period.end * ratio - 8, h);
+                        ctx.lineTo(x + period.end * ratio, h);
+                        ctx.fill();
+                        ctx.closePath();
+                        ctx.stroke();
 
-                        context.beginPath();
-                        context.moveTo(x + period.begin * ratio, h);
-                        context.lineTo(x + period.end * ratio, h);
-                        context.lineTo(x + period.end * ratio, h + 2);
-                        context.lineTo(x + period.begin * ratio, h + 2);
-                        context.lineTo(x + period.begin * ratio, h);
-                        context.fill();
-                        context.closePath();
-                        context.stroke();
+                        ctx.beginPath();
+                        ctx.moveTo(x + period.begin * ratio, h);
+                        ctx.lineTo(x + period.end * ratio, h);
+                        ctx.lineTo(x + period.end * ratio, h + 2);
+                        ctx.lineTo(x + period.begin * ratio, h + 2);
+                        ctx.lineTo(x + period.begin * ratio, h);
+                        ctx.fill();
+                        ctx.closePath();
+                        ctx.stroke();
                     }
-                }
+                });
 
                 h += 30;
 
-                context.beginPath();
-                context.strokeStyle = "#dfdfdf";
-                context.moveTo(0, h - 10);
-                context.lineTo(width, h - 10);
-                context.closePath();
-                context.stroke();
-            }
+                ctx.beginPath();
+                ctx.strokeStyle = "#dfdfdf";
+                ctx.moveTo(0, h - 10);
+                ctx.lineTo(width, h - 10);
+                ctx.closePath();
+                ctx.stroke();
+            });
 
             h = space;
 
-            for (i = 0; i < request.events.length; i++) {
-                var event = request.events[i];
+            mainEvents.forEach(function(event) {
 
-                if (event.totaltime < threshold || 'section.child' == event.name) {
-                    continue;
-                }
-
-                context.fillStyle = "#444";
-                context.font = "12px sans-serif";
-                var text = event.name;
-                var ms;
-                if (event.totaltime < 1) {
-                    ms = " ~ " + event.totaltime + " ms";
-                } else {
-                    ms = " ~ " + parseInt(event.totaltime) + " ms";
-                }
-                if (x + event.starttime * ratio + context.measureText(text + ms).width > width) {
-                    context.textAlign = "end";
-                    context.font = "10px sans-serif";
+                ctx.fillStyle = "#444";
+                ctx.font = "12px sans-serif";
+                text = event.name;
+                ms = " ~ " + (event.totaltime < 1 ? event.totaltime : parseInt(event.totaltime, 10)) + " ms";
+                if (x + event.starttime * ratio + ctx.measureText(text + ms).width > width) {
+                    ctx.textAlign = "end";
+                    ctx.font = "10px sans-serif";
                     xc = x + event.endtime * ratio - 1;
-                    context.fillText(ms, xc, h);
+                    ctx.fillText(ms, xc, h);
 
-                    xc = xc - context.measureText(ms).width
-                    context.font = "12px sans-serif";
-                    context.fillText(text, xc, h);
+                    xc -= ctx.measureText(ms).width;
+                    ctx.font = "12px sans-serif";
+                    ctx.fillText(text, xc, h);
                 } else {
-                    context.textAlign = "start";
-                    context.font = "12px sans-serif";
+                    ctx.textAlign = "start";
+                    ctx.font = "12px sans-serif";
                     xc = x + event.starttime * ratio + 1;
-                    context.fillText(text, xc, h);
+                    ctx.fillText(text, xc, h);
 
-                    xc = xc + context.measureText(text).width;
-                    context.font = "10px sans-serif";
-                    context.fillText(ms, xc, h);
+                    xc += ctx.measureText(text).width;
+                    ctx.font = "10px sans-serif";
+                    ctx.fillText(ms, xc, h);
                 }
 
                 h += 38;
-            }
+            });
         }
 
         function drawCanvases(width)
         {
-            for (k = 0; k < requests_data.requests.length; k++) {
-                drawCanvas(requests_data.requests[k], requests_data.max, {{ threshold }}, width);
-            }
+            "use strict";
+            requests_data.requests.forEach(function(request) {
+                drawCanvas(request, requests_data.max, {{ threshold }}, width);
+            });
         }
 
         var requests_data = {
@@ -272,7 +251,7 @@
         };
 
         drawCanvases({{ width }});
-    </script>
+    //]]></script>
 {% endblock %}
 
 {% macro dump_request_data(token, profile, events, origin) %}
diff --git a/src/Symfony/Component/HttpKernel/Debug/Stopwatch.php b/src/Symfony/Component/HttpKernel/Debug/Stopwatch.php
index 06aa36a8d8..f964d4228b 100644
--- a/src/Symfony/Component/HttpKernel/Debug/Stopwatch.php
+++ b/src/Symfony/Component/HttpKernel/Debug/Stopwatch.php
@@ -76,7 +76,7 @@ class Stopwatch
     public function start($name, $category = null)
     {
         if (!isset($this->events[$name])) {
-            $this->events[$name] = new StopwatchEvent($this->origin, $category);
+            $this->events[$name] = new StopwatchEvent($this->origin ?: microtime(true) * 1000, $category);
         }
 
         return $this->events[$name]->start();
diff --git a/src/Symfony/Component/HttpKernel/Debug/StopwatchEvent.php b/src/Symfony/Component/HttpKernel/Debug/StopwatchEvent.php
index 9796175ae5..f606f1bcd1 100644
--- a/src/Symfony/Component/HttpKernel/Debug/StopwatchEvent.php
+++ b/src/Symfony/Component/HttpKernel/Debug/StopwatchEvent.php
@@ -28,10 +28,12 @@ class StopwatchEvent
      *
      * @param integer $origin   The origin time in milliseconds
      * @param string  $category The event category
+     *
+     * @throws \InvalidArgumentException When the raw time is not valid
      */
     public function __construct($origin, $category = null)
     {
-        $this->origin = $origin;
+        $this->origin = $this->formatTime($origin);
         $this->category = is_string($category) ? $category : 'default';
         $this->started = array();
         $this->periods = array();
@@ -132,7 +134,7 @@ class StopwatchEvent
      */
     public function getEndTime()
     {
-        return count($this->periods) ? $this->periods[count($this->periods) - 1][1] : 0;
+        return ($count = count($this->periods)) ? $this->periods[$count - 1][1] : 0;
     }
 
     /**
@@ -147,11 +149,29 @@ class StopwatchEvent
             $total += $period[1] - $period[0];
         }
 
-        return sprintf('%.1f', $total);
+        return $this->formatTime($total);
     }
 
     private function getNow()
     {
-        return sprintf('%.1f', microtime(true) * 1000 - $this->origin);
+        return $this->formatTime(microtime(true) * 1000 - $this->origin);
+    }
+
+    /**
+     * Formats a time.
+     *
+     * @param numerical $time A raw time
+     *
+     * @return float The formatted time
+     *
+     * @throws \InvalidArgumentException When the raw time is not valid
+     */
+    private function formatTime($time)
+    {
+        if (!is_numeric($time)) {
+            throw new \InvalidArgumentException('The time must be a numerical value');
+        }
+
+        return round($time, 1);
     }
 }
diff --git a/src/Symfony/Component/HttpKernel/Profiler/MongoDbProfilerStorage.php b/src/Symfony/Component/HttpKernel/Profiler/MongoDbProfilerStorage.php
index 5b582d99be..ba03aa32ab 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/MongoDbProfilerStorage.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/MongoDbProfilerStorage.php
@@ -82,7 +82,7 @@ class MongoDbProfilerStorage implements ProfilerStorageInterface
     }
 
     /**
-     * Write data associated with the given token.
+     * Saves a Profile.
      *
      * @param Profile $profile A Profile instance
      *
diff --git a/src/Symfony/Component/HttpKernel/Profiler/Profile.php b/src/Symfony/Component/HttpKernel/Profiler/Profile.php
index 5caf97b71e..bed24f1d10 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/Profile.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/Profile.php
@@ -18,7 +18,7 @@ use Symfony\Component\HttpKernel\DataCollector\DataCollectorInterface;
  *
  * @author Fabien Potencier <fabien@symfony.com>
  */
-class Profile implements \Serializable
+class Profile
 {
     private $token;
     private $collectors;
@@ -212,13 +212,8 @@ class Profile implements \Serializable
         return isset($this->collectors[$name]);
     }
 
-    public function serialize()
+    public function __sleep()
     {
-        return serialize(array($this->token, $this->parent, $this->children, $this->collectors, $this->ip, $this->method, $this->url, $this->time));
-    }
-
-    public function unserialize($data)
-    {
-        list($this->token, $this->parent, $this->children, $this->collectors, $this->ip, $this->method, $this->url, $this->time) = unserialize($data);
+        return array('token', 'parent', 'children', 'collectors', 'ip', 'method', 'url', 'time');
     }
 }
diff --git a/src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php b/src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php
index 3acf65c875..db608eaa18 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php
@@ -42,7 +42,7 @@ interface ProfilerStorageInterface
     function read($token);
 
     /**
-     * Write data associated with the given token.
+     * Saves a Profile.
      *
      * @param Profile $profile A Profile instance
      *
diff --git a/tests/Symfony/Tests/Component/HttpKernel/Debug/StopwatchEventTest.php b/tests/Symfony/Tests/Component/HttpKernel/Debug/StopwatchEventTest.php
index 82da5dad92..9ec05e5284 100644
--- a/tests/Symfony/Tests/Component/HttpKernel/Debug/StopwatchEventTest.php
+++ b/tests/Symfony/Tests/Component/HttpKernel/Debug/StopwatchEventTest.php
@@ -31,7 +31,7 @@ class StopwatchEventTest extends \PHPUnit_Framework_TestCase
         $event = new StopwatchEvent(microtime(true) * 1000);
         $this->assertEquals('default', $event->getCategory());
 
-        $event = new StopwatchEvent(time(), 'cat');
+        $event = new StopwatchEvent(microtime(true) * 1000, 'cat');
         $this->assertEquals('cat', $event->getCategory());
     }
 
@@ -141,4 +141,12 @@ class StopwatchEventTest extends \PHPUnit_Framework_TestCase
         $end = $event->getEndTime();
         $this->assertTrue($end >= 18 && $end <= 30);
     }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     */
+    public function testInvalidOriginThrowsAnException()
+    {
+        new StopwatchEvent("abc");
+    }
 }