diff --git a/C/absmi.c b/C/absmi.c
index 8c45b6e65..1cddc7e99 100644
--- a/C/absmi.c
+++ b/C/absmi.c
@@ -10,8 +10,11 @@
 *									 *
 * File:		absmi.c							 *
 * comments:	Portable abstract machine interpreter                    *
-* Last rev:     $Date: 2008-04-04 16:11:40 $,$Author: vsc $						 *
+* Last rev:     $Date: 2008-06-04 14:47:18 $,$Author: vsc $						 *
 * $Log: not supported by cvs2svn $
+* Revision 1.240  2008/04/04 16:11:40  vsc
+* yapor had gotten broken with recent thread changes
+*
 * Revision 1.239  2008/04/03 13:26:37  vsc
 * protect signal handling with locks for threaded version.
 * fix close/1 entry in manual (obs from Nicos).
@@ -2192,182 +2195,7 @@ Yap_absmi(int inp)
 #endif /* TABLING */
 	trim_trail:
 	  HBREG = PROTECT_FROZEN_H(B->cp_b);
-#ifdef FROZEN_STACKS
-	  {
-	    tr_fr_ptr pt0, pt1, pbase;
-
-	    pbase = B->cp_tr;
-	    pt0 = pt1 = TR - 1;
-	    while (pt1 >= pbase) {
-	      BEGD(d1);
-	      d1 = TrailTerm(pt1);
-	      if (IsVarTerm(d1)) {
-		if (d1 < (CELL)HBREG || d1 > Unsigned(B->cp_b)) { 
-		  TrailTerm(pt0) = d1;
-		  TrailVal(pt0) = TrailVal(pt1);
-		  pt0--;
-		}
-		pt1--;
-	      } else if (IsPairTerm(d1)) {
-		CELL *pt = RepPair(d1);
-#ifdef LIMIT_TABLING
-		if ((ADDR) pt == Yap_TrailBase) {
-		  sg_fr_ptr sg_fr = (sg_fr_ptr) TrailVal(pt1);
-		  SgFr_state(sg_fr)--;  /* complete_in_use --> complete : compiled_in_use --> compiled */
-		  insert_into_global_sg_fr_list(sg_fr);
-		} else
-#endif /* LIMIT_TABLING */
-		  if ((ADDR) pt >= Yap_TrailBase) {
-		    /* skip, this is a problem because we lose information,
-		       namely active references */
-		    pt1 = (tr_fr_ptr)pt;
-		  } else if (IN_BETWEEN(Yap_GlobalBase, pt, H0)) {
-		    CELL val = Deref(*pt);
-		    if (IsVarTerm(val)) {
-		      Bind(pt, MkAtomTerm(AtomCut));
-		      Yap_WakeUp(pt);
-		    }
-		    pt1--;
-		  } else if ((*pt & (LogUpdMask|IndexMask)) == (LogUpdMask|IndexMask)) {
-		    LogUpdIndex *cl = ClauseFlagsToLogUpdIndex(pt);
-		    int erase;
-#if defined(THREADS) || defined(YAPOR)
-		    PredEntry *ap = cl->ClPred;
-#endif
-
-		    LOCK(ap->PELock);
-		    DEC_CLREF_COUNT(cl);
-		    cl->ClFlags &= ~InUseMask;
-		    erase = (cl->ClFlags & (ErasedMask|DirtyMask)) && !(cl->ClRefCount);
-		    if (erase) {
-		      /* at this point, we are the only ones accessing the clause,
-			 hence we don't need to have a lock it */
-		      saveregs();
-		      if (cl->ClFlags & ErasedMask) 
-			Yap_ErLogUpdIndex(cl);
-		      else
-			Yap_CleanUpIndex(cl);
-		      setregs();
-		    }
-		    UNLOCK(ap->PELock);
-		  } else {
-		    TrailTerm(pt0) = d1;
-		    TrailVal(pt0) = TrailVal(pt1);
-		    pt0--;
-		  }
-		pt1--;
-	      } else if (IsApplTerm(d1)) {
-		if (IN_BETWEEN(HBREG,RepAppl(d1),B->cp_b)) {
-		  /* deterministic binding to multi-assignment variable */
-		  pt1 -= 2;
-		} else {
-		  TrailVal(pt0) = TrailVal(pt1);
-		  TrailTerm(pt0) = d1;
-		  TrailVal(pt0-1) = TrailVal(pt1-1);
-		  TrailTerm(pt0-1) = TrailTerm(pt1-1);
-		  pt0 -= 2;
-		  pt1 -= 2;
-		}
-	      } else {
-		TrailTerm(pt0) = d1;
-		TrailVal(pt0) = TrailVal(pt1);
-		pt0--;
-		pt1--;
-	      }
-	      ENDD(d1);                              
-	    }
-	    if (pt0 != pt1) {
-	      int size;
-	      pt0++;
-	      size = TR - pt0;
-	      memcpy(pbase, pt0, size * sizeof(struct trail_frame));
-	      TR = pbase + size;
-	    }
-	  }
-#else
-	  {
-	    tr_fr_ptr pt1, pt0;
-	    pt1 = pt0 = B->cp_tr;
-	    while (pt1 != TR) {
-	      BEGD(d1);
-	      d1 = TrailTerm(pt1);
-	      if (IsVarTerm(d1)) {
-		if (d1 < (CELL)HBREG || d1 > Unsigned(B->cp_b)) { 
-#ifdef FROZEN_STACKS
-		  TrailVal(pt0) = TrailVal(pt1);
-#endif /* FROZEN_STACKS */
-		  TrailTerm(pt0) = d1;
-		  pt0++;
-		}     
-		pt1++;
-	      } else if (IsApplTerm(d1)) {
-		if (IN_BETWEEN(HBREG,RepAppl(d1),B->cp_b)) {
-#ifdef FROZEN_STACKS
-		  pt1 += 2;
-#else
-		  pt1 += 3;
-#endif
-		} else {
-#ifdef FROZEN_STACKS
-		  TrailVal(pt0) = TrailVal(pt1);
-		  TrailTerm(pt0) = d1;
-		  TrailVal(pt0+1) = TrailVal(pt1+1);
-		  TrailTerm(pt0+1) = TrailTerm(pt1+1);
-		  pt0 += 2;
-		  pt1 += 2;
-#else
-		  TrailTerm(pt0+1) = TrailTerm(pt1+1);
-		  TrailTerm(pt0) = TrailTerm(pt0+2) = d1;
-		  pt0 += 3;
-		  pt1 += 3;
-#endif /* FROZEN_STACKS */
-		}
-	      } else if (IsPairTerm(d1)) {
-		CELL *pt = RepPair(d1);
-	      
-		if (IN_BETWEEN(Yap_GlobalBase, pt, H0)) {
-		  CELL val = Deref(*pt);
-		  if (IsVarTerm(val)) {
-		    Bind(VarOfTerm(val), MkAtomTerm(AtomCut));
-		    Yap_WakeUp(pt);
-		  }
-		} else if ((*pt & (LogUpdMask|IndexMask)) == (LogUpdMask|IndexMask)) {
-		  LogUpdIndex *cl = ClauseFlagsToLogUpdIndex(pt);
-#if defined(YAPOR) || defined(THREADS)
-		  PredEntry *ap = cl->ClPred;
-#endif
-		  int erase;
-
-		  LOCK(ap->PELock);
-		  DEC_CLREF_COUNT(cl);
-		  cl->ClFlags &= ~InUseMask;
-		  erase = (cl->ClFlags & (DirtyMask|ErasedMask)) && !(cl->ClRefCount);
-		  if (erase) {
-		    /* at this point, we are the only ones accessing the clause,
-		       hence we don't need to have a lock it */
-		    saveregs();
-		    if (cl->ClFlags & ErasedMask) 
-		      Yap_ErLogUpdIndex(cl);
-		    else
-		      Yap_CleanUpIndex(cl);
-		    setregs();
-		  }
-		  UNLOCK(ap->PELock);
-		} else {
-		  TrailTerm(pt0) = d1;
-		  pt0++;
-		}
-		pt1++;
-	      } else {
-		TrailTerm(pt0) = d1;
-		pt0++;
-		pt1++;
-	      }
-	      ENDD(d1);                              
-	    }
-	    TR = pt0;
-	  }
-#endif /* FROZEN_STACKS */
+#include "trim_trail.h"
 	  B = B->cp_b;
 	  SET_BB(PROTECT_FROZEN_B(B));
 	}
diff --git a/C/c_interface.c b/C/c_interface.c
index 903986744..de8035ad2 100644
--- a/C/c_interface.c
+++ b/C/c_interface.c
@@ -10,8 +10,11 @@
 * File:		c_interface.c						 *
 * comments:	c_interface primitives definition 			 *
 *									 *
-* Last rev:	$Date: 2008-06-04 13:58:36 $,$Author: vsc $						 *
+* Last rev:	$Date: 2008-06-04 14:47:18 $,$Author: vsc $						 *
 * $Log: not supported by cvs2svn $
+* Revision 1.117  2008/06/04 13:58:36  vsc
+* more fixes to C-interface
+*
 * Revision 1.116  2008/04/28 23:02:32  vsc
 * fix bug in current_predicate/2
 * fix bug in c_interface.
@@ -964,6 +967,7 @@ YAP_cut_up(void)
   B = B->cp_b;  /* cut_fail */
 #endif
   HB = B->cp_h; /* cut_fail */
+  Yap_TrimTrail();
 
   RECOVER_B();
 }
@@ -1407,6 +1411,8 @@ YAP_LeaveGoal(int backtrack, YAP_dogoalinfo *dgi)
     DEPTH = B->cp_depth;
 #endif /* DEPTH_LIMIT */
     YENV = ENV = B->cp_env;
+  } else {
+    Yap_TrimTrail();
   }
   /* recover local stack */
   ASP = (CELL *)(B+1);
@@ -1464,6 +1470,7 @@ YAP_RunGoalOnce(Term t)
     CUT_prune_to(cut_pt);
 #endif
     B = cut_pt;
+    Yap_TrimTrail();
   }
   ASP = B->cp_env;
   ENV = (CELL *)ASP[E_E];
@@ -1530,6 +1537,7 @@ YAP_ShutdownGoal(int backtrack)
     ASP = cut_pt->cp_env;
     ENV = (CELL *)ASP[E_E];
     B = (choiceptr)ASP[E_CB];
+    Yap_TrimTrail();
 #ifdef  DEPTH_LIMIT
     DEPTH = ASP[E_DEPTH];
 #endif
@@ -1563,6 +1571,7 @@ YAP_PruneGoal(void)
   }
   B = B->cp_b;
 
+  Yap_TrimTrail();
   RECOVER_B();
 }
 
diff --git a/C/exec.c b/C/exec.c
index 0c45810f5..64b492be2 100644
--- a/C/exec.c
+++ b/C/exec.c
@@ -1789,7 +1789,7 @@ p_restore_regs2(void)
 #endif /* TABLING */
     B = pt0;
     HB = B->cp_h;
-    /*    trim_trail();*/
+    Yap_TrimTrail();
   }
   return(TRUE);
 }
@@ -1852,7 +1852,8 @@ p_cut_up_to_next_disjunction(void) {
     abolish_incomplete_subgoals(B);
 #endif /* TABLING */
   }
-  /* trim_trail(); */
+  HB = B->cp_h;
+  Yap_TrimTrail();
   return TRUE;
 }
 
diff --git a/C/inlines.c b/C/inlines.c
index 455f03e57..3161d6dad 100755
--- a/C/inlines.c
+++ b/C/inlines.c
@@ -801,7 +801,7 @@ p_cut_by( void)
 #endif /* TABLING */
     B = pt0;
     HB = B->cp_h;
-    /*    trim_trail();*/
+    Yap_TrimTrail();
   }
   ENDCHO(pt0);
   return(TRUE);
diff --git a/C/unify.c b/C/unify.c
index 0dd18c348..40f64f2bc 100644
--- a/C/unify.c
+++ b/C/unify.c
@@ -680,3 +680,8 @@ Yap_InitAbsmi(void)
 #endif
 }
 
+void
+Yap_TrimTrail(void)
+{
+#include "trim_trail.h"
+}
diff --git a/H/Yapproto.h b/H/Yapproto.h
index 7c8c906f0..9c0cbc4bf 100644
--- a/H/Yapproto.h
+++ b/H/Yapproto.h
@@ -10,7 +10,7 @@
 * File:		Yap.proto						 *
 * mods:									 *
 * comments:	Function declarations for YAP				 *
-* version:      $Id: Yapproto.h,v 1.85 2008-03-27 00:41:32 vsc Exp $	 *
+* version:      $Id: Yapproto.h,v 1.86 2008-06-04 14:47:18 vsc Exp $	 *
 *************************************************************************/
 
 /* prototype file for Yap */
@@ -325,6 +325,7 @@ void	STD_PROTO(Yap_InitLowLevelTrace,(void));
 /* unify.c */
 void         STD_PROTO(Yap_InitAbsmi,(void));
 void         STD_PROTO(Yap_InitUnify,(void));
+void         STD_PROTO(Yap_TrimTrail,(void));
 int          STD_PROTO(Yap_IUnify,(register CELL d0,register CELL d1));
 
 /* userpreds.c */
diff --git a/H/trim_trail.h b/H/trim_trail.h
new file mode 100644
index 000000000..79cd58bb0
--- /dev/null
+++ b/H/trim_trail.h
@@ -0,0 +1,176 @@
+#ifdef FROZEN_STACKS
+  {
+    tr_fr_ptr pt0, pt1, pbase;
+
+    pbase = B->cp_tr;
+    pt0 = pt1 = TR - 1;
+    while (pt1 >= pbase) {
+      BEGD(d1);
+      d1 = TrailTerm(pt1);
+      if (IsVarTerm(d1)) {
+	if (d1 < (CELL)HBREG || d1 > Unsigned(B->cp_b)) { 
+	  TrailTerm(pt0) = d1;
+	  TrailVal(pt0) = TrailVal(pt1);
+	  pt0--;
+	}
+	pt1--;
+      } else if (IsPairTerm(d1)) {
+	CELL *pt = RepPair(d1);
+#ifdef LIMIT_TABLING
+	if ((ADDR) pt == Yap_TrailBase) {
+	  sg_fr_ptr sg_fr = (sg_fr_ptr) TrailVal(pt1);
+	  SgFr_state(sg_fr)--;  /* complete_in_use --> complete : compiled_in_use --> compiled */
+	  insert_into_global_sg_fr_list(sg_fr);
+	} else
+#endif /* LIMIT_TABLING */
+	  if ((ADDR) pt >= Yap_TrailBase) {
+	    /* skip, this is a problem because we lose information,
+	       namely active references */
+	    pt1 = (tr_fr_ptr)pt;
+	  } else if (IN_BETWEEN(Yap_GlobalBase, pt, H0)) {
+	    CELL val = Deref(*pt);
+	    if (IsVarTerm(val)) {
+	      Bind(pt, MkAtomTerm(AtomCut));
+	      Yap_WakeUp(pt);
+	    }
+	    pt1--;
+	  } else if ((*pt & (LogUpdMask|IndexMask)) == (LogUpdMask|IndexMask)) {
+	    LogUpdIndex *cl = ClauseFlagsToLogUpdIndex(pt);
+	    int erase;
+#if defined(THREADS) || defined(YAPOR)
+	    PredEntry *ap = cl->ClPred;
+#endif
+	    
+	    LOCK(ap->PELock);
+	    DEC_CLREF_COUNT(cl);
+	    cl->ClFlags &= ~InUseMask;
+	    erase = (cl->ClFlags & (ErasedMask|DirtyMask)) && !(cl->ClRefCount);
+	    if (erase) {
+	      /* at this point, we are the only ones accessing the clause,
+		 hence we don't need to have a lock it */
+	      saveregs();
+	      if (cl->ClFlags & ErasedMask) 
+		Yap_ErLogUpdIndex(cl);
+	      else
+		Yap_CleanUpIndex(cl);
+	      setregs();
+	    }
+	    UNLOCK(ap->PELock);
+	  } else {
+	    TrailTerm(pt0) = d1;
+	    TrailVal(pt0) = TrailVal(pt1);
+	    pt0--;
+	  }
+	pt1--;
+      } else if (IsApplTerm(d1)) {
+	if (IN_BETWEEN(HBREG,RepAppl(d1),B->cp_b)) {
+	  /* deterministic binding to multi-assignment variable */
+	  pt1 -= 2;
+	} else {
+	  TrailVal(pt0) = TrailVal(pt1);
+	  TrailTerm(pt0) = d1;
+	  TrailVal(pt0-1) = TrailVal(pt1-1);
+	  TrailTerm(pt0-1) = TrailTerm(pt1-1);
+	  pt0 -= 2;
+	  pt1 -= 2;
+	}
+      } else {
+	TrailTerm(pt0) = d1;
+	TrailVal(pt0) = TrailVal(pt1);
+	pt0--;
+	pt1--;
+      }
+      ENDD(d1);                              
+    }
+    if (pt0 != pt1) {
+      int size;
+      pt0++;
+      size = TR - pt0;
+      memcpy(pbase, pt0, size * sizeof(struct trail_frame));
+      TR = pbase + size;
+    }
+  }
+#else
+  {
+    tr_fr_ptr pt1, pt0;
+    pt1 = pt0 = B->cp_tr;
+    while (pt1 != TR) {
+      BEGD(d1);
+      d1 = TrailTerm(pt1);
+      if (IsVarTerm(d1)) {
+	if (d1 < (CELL)HBREG || d1 > Unsigned(B->cp_b)) { 
+#ifdef FROZEN_STACKS
+	  TrailVal(pt0) = TrailVal(pt1);
+#endif /* FROZEN_STACKS */
+	  TrailTerm(pt0) = d1;
+	  pt0++;
+	}     
+	pt1++;
+      } else if (IsApplTerm(d1)) {
+	if (IN_BETWEEN(HBREG,RepAppl(d1),B->cp_b)) {
+#ifdef FROZEN_STACKS
+	  pt1 += 2;
+#else
+	  pt1 += 3;
+#endif
+	} else {
+#ifdef FROZEN_STACKS
+	  TrailVal(pt0) = TrailVal(pt1);
+	  TrailTerm(pt0) = d1;
+	  TrailVal(pt0+1) = TrailVal(pt1+1);
+	  TrailTerm(pt0+1) = TrailTerm(pt1+1);
+	  pt0 += 2;
+	  pt1 += 2;
+#else
+	  TrailTerm(pt0+1) = TrailTerm(pt1+1);
+	  TrailTerm(pt0) = TrailTerm(pt0+2) = d1;
+	  pt0 += 3;
+	  pt1 += 3;
+#endif /* FROZEN_STACKS */
+	}
+      } else if (IsPairTerm(d1)) {
+	CELL *pt = RepPair(d1);
+	      
+	if (IN_BETWEEN(Yap_GlobalBase, pt, H0)) {
+	  CELL val = Deref(*pt);
+	  if (IsVarTerm(val)) {
+	    Bind(VarOfTerm(val), MkAtomTerm(AtomCut));
+	    Yap_WakeUp(pt);
+	  }
+	} else if ((*pt & (LogUpdMask|IndexMask)) == (LogUpdMask|IndexMask)) {
+	  LogUpdIndex *cl = ClauseFlagsToLogUpdIndex(pt);
+#if defined(YAPOR) || defined(THREADS)
+	  PredEntry *ap = cl->ClPred;
+#endif
+	  int erase;
+
+	  LOCK(ap->PELock);
+	  DEC_CLREF_COUNT(cl);
+	  cl->ClFlags &= ~InUseMask;
+	  erase = (cl->ClFlags & (DirtyMask|ErasedMask)) && !(cl->ClRefCount);
+	  if (erase) {
+	    /* at this point, we are the only ones accessing the clause,
+	       hence we don't need to have a lock it */
+	    saveregs();
+	    if (cl->ClFlags & ErasedMask) 
+	      Yap_ErLogUpdIndex(cl);
+	    else
+	      Yap_CleanUpIndex(cl);
+	    setregs();
+	  }
+	  UNLOCK(ap->PELock);
+	} else {
+	  TrailTerm(pt0) = d1;
+	  pt0++;
+	}
+	pt1++;
+      } else {
+	TrailTerm(pt0) = d1;
+	pt0++;
+	pt1++;
+      }
+      ENDD(d1);                              
+    }
+    TR = pt0;
+  }
+#endif /* FROZEN_STACKS */
diff --git a/Makefile.in b/Makefile.in
index 8bd2b1d9a..c3e0dfb64 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -111,8 +111,9 @@ HEADERS = \
 	$(srcdir)/H/index.h $(srcdir)/H/iopreds.h \
 	$(srcdir)/H/rclause.h \
 	$(srcdir)/H/rheap.h \
-	$(srcdir)/H/tracer.h \
 	$(srcdir)/H/threads.h \
+	$(srcdir)/H/tracer.h \
+	$(srcdir)/H/trim_trail.h \
 	$(srcdir)/H/yapio.h \
 	$(srcdir)/BEAM/eam.h $(srcdir)/BEAM/eamamasm.h \
 	$(srcdir)/OPTYap/opt.config.h \