diff --git a/C/absmi.c b/C/absmi.c
index 4cc37f514..9cda0fc86 100644
--- a/C/absmi.c
+++ b/C/absmi.c
@@ -2155,6 +2155,37 @@ Yap_absmi(int inp)
       /* don't do debugging and friends here */
       goto do_comit_b_x;
 
+      /* don't forget I cannot creep at deallocate (where to?) */
+      /* also, this is unusual in that I have already done deallocate,
+	 so I don't need to redo it.
+       */ 
+    NoStackDeallocate:
+      if (CFREG == (CELL)(LCL0+2)) {
+	JMPNext();
+      }
+      ASP = YREG;
+      if (CFREG == (CELL)(LCL0+1)) {
+	goto noheapleft;
+      }
+      if (CFREG == Unsigned(LCL0)) {
+	if (Yap_ReadTimedVar(WokenGoals) != TermNil) {
+	  SREG = (CELL *)RepPredProp(Yap_GetPredPropByAtom(AtomTrue,0));
+	  goto creep;
+	} else {
+	  CFREG = CalculateStackGap();
+	  JMPNext();
+	}
+      }
+      if (CFREG != CalculateStackGap()) {
+	goto either_notest;
+      }
+      saveregs();
+      if (!Yap_gc(0, ENV, CPREG)) {
+	Yap_Error(OUT_OF_STACK_ERROR,TermNil,Yap_ErrorMessage);
+      }
+      setregs();
+      JMPNext();
+
       /* don't forget I cannot creep at ; */
     NoStackEither:
       /* find something to fool S */
@@ -2548,31 +2579,41 @@ Yap_absmi(int inp)
       ENDOp();
 
       Op(deallocate, e);
+      CACHE_Y_AS_ENV(YREG);
       PREG = NEXTOP(PREG, e);
       /* other instructions do depend on S being set by deallocate
 	 :-( */
       SREG = YREG;
-      CPREG = (yamop *) YREG[E_CP];
-      ENV = YREG = (CELL *) YREG[E_E];
+      CPREG = (yamop *) E_YREG[E_CP];
+      ENV = E_YREG = (CELL *) E_YREG[E_E];
 #ifdef DEPTH_LIMIT
-      DEPTH = YREG[E_DEPTH];
+      DEPTH = E_YREG[E_DEPTH];
 #endif	/* DEPTH_LIMIT */
 #ifdef FROZEN_STACKS
       { 
 	choiceptr top_b = PROTECT_FROZEN_B(B);
 #ifdef SBA
-	if (YREG > (CELL *) top_b || YREG < H) YREG = (CELL *) top_b;
+	if (E_YREG > (CELL *) top_b || E_YREG < H) E_YREG = (CELL *) top_b;
 #else
-	if (YREG > (CELL *) top_b) YREG = (CELL *) top_b;
+	if (E_YREG > (CELL *) top_b) E_YREG = (CELL *) top_b;
 #endif
-	else YREG = (CELL *)((CELL) YREG + ENV_Size(CPREG));
+	else E_YREG = (CELL *)((CELL) E_YREG + ENV_Size(CPREG));
       }
 #else
-      if (YREG > (CELL *) B)
-	YREG = (CELL *) B;
+      if (E_YREG > (CELL *) B)
+	E_YREG = (CELL *) B;
       else
-	YREG = (CELL *) ((CELL) YREG + ENV_Size(CPREG));
+	E_YREG = (CELL *) ((CELL) E_YREG + ENV_Size(CPREG));
 #endif /* FROZEN_STACKS */
+#ifndef NO_CHECKING
+      if (Yap_do_low_level_trace) {
+	fprintf(stderr, "H is %p, YENV is %p\n", H, YENV);
+      }
+      /* check stacks */
+      check_stack(NoStackDeallocate, H);
+#endif
+      WRITEBACK_Y_AS_ENV();
+      ENDCACHE_Y_AS_ENV();
       GONext();
       ENDOp();
 
diff --git a/C/bignum.c b/C/bignum.c
index d5ed9f864..b040e4373 100644
--- a/C/bignum.c
+++ b/C/bignum.c
@@ -98,8 +98,6 @@ AllocBigNumSpace(size_t size)
   size = AdjustSize(size)/CellSize;
   alloc_ptr[0] = size;
   alloc_ptr += size+1;
-  if (alloc_ptr > ASP-1024)
-    Yap_Error(SYSTEM_ERROR,TermNil,"no space for bignum");
   return(ret);
 }
 
@@ -116,8 +114,6 @@ ReAllocBigNumSpace(void *optr, size_t osize, size_t size)
   if (((CELL *)optr)+osize == alloc_ptr) {
     alloc_ptr += (size-osize);
     ((CELL *)optr)[-1] = size;
-    if (alloc_ptr > ASP-1024)
-      Yap_Error(SYSTEM_ERROR,TermNil,"no space for bignum");
     return(optr);
   }
   out = AllocBigNumSpace(size);
diff --git a/C/computils.c b/C/computils.c
index 68e352d54..e6bdff242 100644
--- a/C/computils.c
+++ b/C/computils.c
@@ -552,7 +552,8 @@ static char *opformat[] =
   "try_me_else\t\t%l\t%x",
   "jump\t\t%l",
   "jump\t\t%l",
-  "procceed",
+  "proceed",
+  "safe_proceed",
   "call\t\t%p,%d,%z",
   "execute\t\t%p",
   "sys\t\t%p",
diff --git a/C/dbase.c b/C/dbase.c
index f3d730b53..80f2183ca 100644
--- a/C/dbase.c
+++ b/C/dbase.c
@@ -3227,7 +3227,8 @@ c_recorded(int flags)
 
 static Int
 lu_recorded(PredEntry *pe) {
-  if (Yap_op_from_opcode(P->opc) == _procceed) {
+  op_numbers opc = Yap_op_from_opcode(P->opc);
+  if (opc == _procceed) {
     P = pe->CodeOfPred;
   } else {
     CP = P;
diff --git a/C/tracer.c b/C/tracer.c
index c9a136891..62064db07 100644
--- a/C/tracer.c
+++ b/C/tracer.c
@@ -113,10 +113,6 @@ low_level_trace(yap_low_level_port port, PredEntry *pred, CELL *args)
   /*  extern int gc_calls; */
 
   vsc_count++;
-  if (vsc_count < 1077000) {
-    return;
-  }
-  if (vsc_count == 1077205LL) vsc_xstop = 1;
 #ifdef COMMENTED
   if (vsc_count < 123536430LL) {
     if (vsc_count == 123536441LL) vsc_xstop = 1;