diff --git a/actions/profilecompletion.php b/actions/profilecompletion.php
index 045bf68a7f..00dbe9d29d 100644
--- a/actions/profilecompletion.php
+++ b/actions/profilecompletion.php
@@ -179,8 +179,7 @@ class ProfilecompletionAction extends Action
             else {
                 $cnt = $profile->find();
             }
-            // @todo FIXME: Call-time pass-by-reference has been deprecated.
-            Event::handle('EndProfileCompletionSearch', $this, &$profile, $search_engine);
+            Event::handle('EndProfileCompletionSearch', $this, $profile, $search_engine);
         }
 
         while ($profile->fetch()) {
diff --git a/lib/daemon.php b/lib/daemon.php
index 4c2491e97b..c09531c9d5 100644
--- a/lib/daemon.php
+++ b/lib/daemon.php
@@ -48,6 +48,17 @@ class Daemon
 
     function background()
     {
+        /* Starting PHP 5.4 (dotdeb), maybe earlier for some version/distrib
+         * seems MySQL connection using mysqli driver get lost when fork.
+         * Need to unset it so that child process recreate it.
+         *
+         * Not needed if using mysql driver (but it's deprecated starting PHP 5.5)
+         *
+         * @todo FIXME cleaner way to do it ?
+         */
+        global $_DB_DATAOBJECT;
+        unset($_DB_DATAOBJECT['CONNECTIONS']);
+
         $pid = pcntl_fork();
         if ($pid < 0) { // error
             common_log(LOG_ERR, "Could not fork.");
diff --git a/plugins/Aim/AimPlugin.php b/plugins/Aim/AimPlugin.php
index e44505b21c..ffb9345877 100644
--- a/plugins/Aim/AimPlugin.php
+++ b/plugins/Aim/AimPlugin.php
@@ -109,7 +109,7 @@ class AimPlugin extends ImPlugin
 
     function onStartImDaemonIoManagers(&$classes)
     {
-        parent::onStartImDaemonIoManagers(&$classes);
+        parent::onStartImDaemonIoManagers($classes);
         $classes[] = new AimManager($this); // handles sending/receiving
         return true;
     }
diff --git a/plugins/DomainStatusNetwork/lib/domainstatusnetworkinstaller.php b/plugins/DomainStatusNetwork/lib/domainstatusnetworkinstaller.php
index a30ab110ab..dd93a51153 100644
--- a/plugins/DomainStatusNetwork/lib/domainstatusnetworkinstaller.php
+++ b/plugins/DomainStatusNetwork/lib/domainstatusnetworkinstaller.php
@@ -267,6 +267,9 @@ class DomainStatusNetworkInstaller extends Installer
     function createDatabase()
     {
         // Create the New DB
+        /* FIXME
+         * Extension 'mysql_' is deprecated since PHP 5.5 - use mysqli instead.
+         */
         $res = mysql_connect($this->host, $this->rootname, $this->rootpass);
         if (!$res) {
             throw new ServerException("Cannot connect to {$this->host} as {$this->rootname}.");
diff --git a/plugins/Irc/IrcPlugin.php b/plugins/Irc/IrcPlugin.php
index 2c52bb99bd..f74324c186 100644
--- a/plugins/Irc/IrcPlugin.php
+++ b/plugins/Irc/IrcPlugin.php
@@ -147,7 +147,7 @@ class IrcPlugin extends ImPlugin {
      * @return boolean
      */
     public function onStartImDaemonIoManagers(&$classes) {
-        parent::onStartImDaemonIoManagers(&$classes);
+        parent::onStartImDaemonIoManagers($classes);
         $classes[] = new IrcManager($this); // handles sending/receiving
         return true;
     }
diff --git a/plugins/Msn/MsnPlugin.php b/plugins/Msn/MsnPlugin.php
index ccc190334d..fdef94ce55 100644
--- a/plugins/Msn/MsnPlugin.php
+++ b/plugins/Msn/MsnPlugin.php
@@ -120,7 +120,7 @@ class MsnPlugin extends ImPlugin {
      * @return boolean
      */
     public function onStartImDaemonIoManagers(&$classes) {
-        parent::onStartImDaemonIoManagers(&$classes);
+        parent::onStartImDaemonIoManagers($classes);
         $classes[] = new MsnManager($this); // handles sending/receiving
         return true;
     }
diff --git a/plugins/TwitterBridge/TwitterBridgePlugin.php b/plugins/TwitterBridge/TwitterBridgePlugin.php
index cae0dbfcac..672c1b8451 100644
--- a/plugins/TwitterBridge/TwitterBridgePlugin.php
+++ b/plugins/TwitterBridge/TwitterBridgePlugin.php
@@ -249,7 +249,7 @@ class TwitterBridgePlugin extends Plugin
      *
      * @return boolean hook return
      */
-    function onGetValidDaemons($daemons)
+    function onGetValidDaemons(&$daemons)
     {
         if (self::hasKeys()) {
             array_push(
diff --git a/plugins/Xmpp/XmppPlugin.php b/plugins/Xmpp/XmppPlugin.php
index 74e104d974..f56d33f0a3 100644
--- a/plugins/Xmpp/XmppPlugin.php
+++ b/plugins/Xmpp/XmppPlugin.php
@@ -310,7 +310,7 @@ class XmppPlugin extends ImPlugin
 
     function onStartImDaemonIoManagers(&$classes)
     {
-        parent::onStartImDaemonIoManagers(&$classes);
+        parent::onStartImDaemonIoManagers($classes);
         $classes[] = new XmppManager($this); // handles pings/reconnects
         return true;
     }
@@ -440,7 +440,7 @@ class XmppPlugin extends ImPlugin
      *
      * @return boolean hook return
      */
-    function onGetValidDaemons($daemons)
+    function onGetValidDaemons(&$daemons)
     {
         if( isset($this->server) &&
             isset($this->port)   &&