diff --git a/C/absmi.c b/C/absmi.c
index 805ff4ca5..2c6749ca9 100644
--- a/C/absmi.c
+++ b/C/absmi.c
@@ -10,8 +10,11 @@
 *									 *
 * File:		absmi.c							 *
 * comments:	Portable abstract machine interpreter                    *
-* Last rev:     $Date: 2004-04-22 20:07:02 $,$Author: vsc $						 *
+* Last rev:     $Date: 2004-04-29 03:45:49 $,$Author: vsc $						 *
 * $Log: not supported by cvs2svn $
+* Revision 1.131  2004/04/22 20:07:02  vsc
+* more fixes for USE_SYSTEM_MEMORY
+*
 * Revision 1.130  2004/04/22 03:24:17  vsc
 * trust_logical should protect the last clause, otherwise it cannot
 * jump there.
@@ -1239,7 +1242,7 @@ Yap_absmi(int inp)
 	}
 #else
 	if (TrailTerm(B->cp_tr-1) == CLREF_TO_TRENTRY(cl) &&
-	    B->cp_tr > B->cp_b->cp_tr) {
+	    B->cp_tr != B->cp_b->cp_tr) {
 	  cl->ClFlags &= ~InUseMask;
 	  TR = --B->cp_tr;
 	  /* next, recover space for the indexing code if it was erased */
@@ -11627,7 +11630,7 @@ Yap_absmi(int inp)
       CPREG = NEXTOP(PREG, sla);
       goto creep;
 
-      BOp(p_execute_tail, e);
+      BOp(p_execute_tail, sla);
       {
 	PredEntry *pen;
 	Term mod;
@@ -11845,6 +11848,8 @@ Yap_absmi(int inp)
 	WRITEBACK_Y_AS_ENV();
 	SREG = (CELL *) pen;
 	ASP = E_YREG;
+	if (ASP > (CELL *)B)
+	  ASP = (CELL *)B;
 	LOCK(SignalLock);
 	ActiveSignals &= ~YAP_CDOVF_SIGNAL;
 	UNLOCK(SignalLock);
@@ -11863,9 +11868,6 @@ Yap_absmi(int inp)
 	if (ActiveSignals) {
 	  goto creep;
 	}
-	ASP = (CELL *) (((char *) YREG) + PREG->u.sla.s);
-	if (ASP > (CELL *)B)
-	  ASP = (CELL *)B;
 	saveregs();
 	if (!Yap_gc(((PredEntry *)SREG)->ArityOfPE, ENV, NEXTOP(PREG, sla))) {
 	  Yap_Error(OUT_OF_STACK_ERROR,TermNil,Yap_ErrorMessage);
diff --git a/C/amasm.c b/C/amasm.c
index 8b7e84e17..47e3fe16b 100644
--- a/C/amasm.c
+++ b/C/amasm.c
@@ -11,8 +11,11 @@
 * File:		amasm.c							 *
 * comments:	abstract machine assembler				 *
 *									 *
-* Last rev:     $Date: 2004-04-22 20:07:04 $							 *
+* Last rev:     $Date: 2004-04-29 03:45:50 $							 *
 * $Log: not supported by cvs2svn $
+* Revision 1.60  2004/04/22 20:07:04  vsc
+* more fixes for USE_SYSTEM_MEMORY
+*
 * Revision 1.59  2004/03/31 01:03:09  vsc
 * support expand group of clauses
 *
@@ -2925,6 +2928,11 @@ Yap_InitComma(void)
       GONEXT(e);
     }
     code_p->opc = opcode(_p_execute_tail);
-    GONEXT(e);
+    code_p->u.sla.s = emit_count(-Signed(RealEnvSize)-3*sizeof(CELL));
+    code_p->u.sla.bmap = NULL;
+    code_p->u.sla.sla_u.p = 
+      code_p->u.sla.p0 =
+      RepPredProp(PredPropByFunc(FunctorComma,0));
+    GONEXT(sla);
   }
 }
diff --git a/C/attvar.c b/C/attvar.c
index 7d76840fa..2902058bd 100644
--- a/C/attvar.c
+++ b/C/attvar.c
@@ -352,7 +352,6 @@ BuildNewAttVar(Term t, Int i, Term tatt)
     H -= 2;
     t = H[0];
     tatt = H[1];
-    printf("attv is %p\n", attv);
     attv = (attvar_record *)Yap_ReadTimedVar(DelayedVars);
   }
   time = InitVarTime();
diff --git a/C/heapgc.c b/C/heapgc.c
index f54c450bb..156536e68 100644
--- a/C/heapgc.c
+++ b/C/heapgc.c
@@ -1397,6 +1397,9 @@ mark_choicepoints(register choiceptr gc_B, tr_fr_ptr saved_TR, int very_verbose)
 #ifdef EASY_SHUNTING
     HB = H;
 #endif
+    yamop *lu_cl0 = NEXTOP(PredLogUpdClause0->CodeOfPred,ld), *lu_cl = NEXTOP(PredLogUpdClause->CodeOfPred,ld), *su_cl = NEXTOP(PredStaticClause->CodeOfPred,ld);
+
+
   while (gc_B != NULL) {
     op_numbers opnum;
     register OPCODE op;
@@ -1701,6 +1704,12 @@ mark_choicepoints(register choiceptr gc_B, tr_fr_ptr saved_TR, int very_verbose)
       case _trust_me4:
       case _retry:
       case _trust:
+	if (gc_B->cp_ap == lu_cl0 ||
+	    gc_B->cp_ap == lu_cl ||
+	    gc_B->cp_ap == su_cl) {
+	  CELL *pt = (CELL *)IntegerOfTerm(gc_B->cp_args[1]);
+	  mark_db_fixed(pt);
+	}
 	nargs = rtp->u.ld.s;
 	break;
       default:
diff --git a/C/tracer.c b/C/tracer.c
index 96ac6e6cd..469f01735 100644
--- a/C/tracer.c
+++ b/C/tracer.c
@@ -127,6 +127,8 @@ low_level_trace(yap_low_level_port port, PredEntry *pred, CELL *args)
   }
 #endif
   vsc_count++;
+  if (vsc_count < 16489200)
+    return;
 #ifdef COMMENTED
   //  if (vsc_count == 218280)
   //    vsc_xstop = 1;
@@ -154,7 +156,7 @@ low_level_trace(yap_low_level_port port, PredEntry *pred, CELL *args)
   if (vsc_count < 5530257LL) {
     return;
   }
-  if (vsc_count == ) {
+  if (vsc_count == 9414280LL) {
     vsc_xstop = TRUE;
   }
   if (vsc_count < 3399741LL) {
diff --git a/H/rheap.h b/H/rheap.h
index a44deca86..fd9b403fc 100644
--- a/H/rheap.h
+++ b/H/rheap.h
@@ -11,8 +11,11 @@
 * File:		rheap.h							 *
 * comments:	walk through heap code					 *
 *									 *
-* Last rev:     $Date: 2004-03-31 01:03:10 $,$Author: vsc $						 *
+* Last rev:     $Date: 2004-04-29 03:45:50 $,$Author: vsc $						 *
 * $Log: not supported by cvs2svn $
+* Revision 1.40  2004/03/31 01:03:10  vsc
+* support expand group of clauses
+*
 * Revision 1.39  2004/03/19 11:35:42  vsc
 * trim_trail for default machine
 * be more aggressive about try-retry-trust chains.
@@ -656,7 +659,6 @@ restore_opcodes(yamop *pc)
     case _p_dif:
     case _p_eq:
     case _p_functor:
-    case _p_execute_tail:
     case _enter_a_profiling:
     case _count_a_call:
     case _index_dbref:
@@ -757,6 +759,7 @@ restore_opcodes(yamop *pc)
       pc = NEXTOP(pc,yF);
       break;
       /* instructions type sla */      
+    case _p_execute_tail:
     case _p_execute:
       pc->u.sla.sla_u.p = PtoPredAdjust(pc->u.sla.sla_u.p);
       if (pc->u.sla.sla_u.mod != 0) {