diff --git a/src/IntWalk/IntWalk_PWalking.cxx b/src/IntWalk/IntWalk_PWalking.cxx
index eed1c6334a..92298b01c3 100644
--- a/src/IntWalk/IntWalk_PWalking.cxx
+++ b/src/IntWalk/IntWalk_PWalking.cxx
@@ -729,7 +729,7 @@ void IntWalk_PWalking::Perform(const TColStd_Array1OfReal& ParDep,
   previousd  = myIntersectionOn2S.Direction();
   previousd1 = myIntersectionOn2S.DirectionOnS1();
   previousd2 = myIntersectionOn2S.DirectionOnS2();
-  indextg = 1;
+  myTangentIdx = 1;
   tgdir   = previousd;
   firstd1 = previousd1;
   firstd2 = previousd2;
@@ -748,7 +748,7 @@ void IntWalk_PWalking::Perform(const TColStd_Array1OfReal& ParDep,
   if(IsTangentExtCheck(Caro1, Caro2, Param(1), Param(2), Param(3), Param(4), myTolTang, pasuv))
     return;
 
-  AddAPoint(line,previousPoint);
+  AddAPoint(previousPoint);
   //
   IntWalk_StatusDeflection aStatus = IntWalk_OK, aPrevStatus = IntWalk_OK;
   Standard_Boolean NoTestDeflection = Standard_False;
@@ -1251,7 +1251,7 @@ void IntWalk_PWalking::Perform(const TColStd_Array1OfReal& ParDep,
                       }
                     }
                     //
-                    AddAPoint(line,previousPoint);
+                    AddAPoint(previousPoint);
                     RejectIndex++;
 
                     if(RejectIndex >= RejectIndexMAX)
@@ -1287,7 +1287,7 @@ void IntWalk_PWalking::Perform(const TColStd_Array1OfReal& ParDep,
               if(close)
               {
                 //================= la ligne est fermee ===============
-                AddAPoint(line,line->Value(1)); //ligne fermee
+                AddAPoint(line->Value(1)); //ligne fermee
                 LevelOfIterWithoutAppend=0;
               }
               else    //$$$
@@ -1339,7 +1339,7 @@ void IntWalk_PWalking::Perform(const TColStd_Array1OfReal& ParDep,
                         }
                       }
                       //
-                      AddAPoint(line,previousPoint);
+                      AddAPoint(previousPoint);
                       RejectIndex++;
 
                       if(RejectIndex >= RejectIndexMAX)
@@ -1573,7 +1573,7 @@ void IntWalk_PWalking::Perform(const TColStd_Array1OfReal& ParDep,
                         }//if (previoustg) cond.
 
                         ////////////////////////////////////////
-                        AddAPoint(line,previousPoint);
+                        AddAPoint(previousPoint);
                         RejectIndex++;
 
                         if(RejectIndex >= RejectIndexMAX)
@@ -2031,7 +2031,7 @@ Standard_Boolean IntWalk_PWalking::ExtendLineInCommonZone(const IntImp_ConstIsop
   Standard_Integer i = 0;
 
   for(i = 1; i <= aSeqOfNewPoint.Length(); i++) {
-    AddAPoint(line, aSeqOfNewPoint.Value(i));
+    AddAPoint(aSeqOfNewPoint.Value(i));
   }
 
   return bOutOfTangentZone;
@@ -2440,7 +2440,7 @@ Standard_Boolean IntWalk_PWalking::
         break;
       }
 
-      line->RemovePoint(1);
+      RemoveAPoint(1);
     }
 
     line->InsertBefore(1, anIP);
@@ -2481,7 +2481,7 @@ Standard_Boolean IntWalk_PWalking::
         break;
       }
 
-      line->RemovePoint(aNbPnts);
+      RemoveAPoint(aNbPnts);
     }
 
     line->Add(anIP);
@@ -2839,14 +2839,14 @@ RepartirOuDiviser(Standard_Boolean& DejaReparti,
   //  Standard_Integer i;
   if (Arrive) {    //restart in the other direction
     if (!DejaReparti ) {
-      Arrive        = Standard_False; 
-      DejaReparti   = Standard_True;
+      Arrive = Standard_False;
+      DejaReparti = Standard_True;
       previousPoint = line->Value(1);
-      previoustg    = Standard_False;
-      previousd1    = firstd1;
-      previousd2    = firstd2;
-      previousd     = tgdir;
-      indextg       = line->NbPoints();
+      previoustg = Standard_False;
+      previousd1 = firstd1;
+      previousd2 = firstd2;
+      previousd = tgdir;
+      myTangentIdx = line->NbPoints();
       tgdir.Reverse();
       line->Reverse();
 
@@ -2886,14 +2886,15 @@ RepartirOuDiviser(Standard_Boolean& DejaReparti,
           tglast = Standard_True;      // IS IT ENOUGH ????
         }
 
-        if (!DejaReparti) {  //restart in the other direction
-          DejaReparti       = Standard_True;
-          previousPoint     = line->Value(1);
-          previoustg        = Standard_False;
-          previousd1        = firstd1;
-          previousd2        = firstd2;
-          previousd         = tgdir;
-          indextg           = line->NbPoints();
+        if (!DejaReparti)
+        {  //restart in the other direction
+          DejaReparti = Standard_True;
+          previousPoint = line->Value(1);
+          previoustg = Standard_False;
+          previousd1 = firstd1;
+          previousd2 = firstd2;
+          previousd = tgdir;
+          myTangentIdx = line->NbPoints();
           tgdir.Reverse();
           line->Reverse();
 
diff --git a/src/IntWalk/IntWalk_PWalking.hxx b/src/IntWalk/IntWalk_PWalking.hxx
index e4dab8ed9a..9fe04b72be 100644
--- a/src/IntWalk/IntWalk_PWalking.hxx
+++ b/src/IntWalk/IntWalk_PWalking.hxx
@@ -132,7 +132,27 @@ public:
   
   Standard_EXPORT void RepartirOuDiviser (Standard_Boolean& DejaReparti, IntImp_ConstIsoparametric& ChoixIso, Standard_Boolean& Arrive);
   
-    void AddAPoint (Handle(IntSurf_LineOn2S)& line, const IntSurf_PntOn2S& POn2S);
+  //! Inserts thePOn2S in the end of line
+  void AddAPoint (const IntSurf_PntOn2S& thePOn2S);
+
+  //! Removes point with index theIndex from line.
+  //! If theIndex is greater than the number of points in line
+  //! then the last point will be removed.
+  //! theIndex must be started with 1.
+  void RemoveAPoint(const Standard_Integer theIndex)
+  {
+    const Standard_Integer anIdx = Min(theIndex, line->NbPoints());
+    
+    if (anIdx < 1)
+      return;
+
+    if (anIdx <= myTangentIdx)
+    {
+      myTangentIdx--;
+    }
+
+    line->RemovePoint(anIdx);
+  }
   
   Standard_EXPORT Standard_Boolean PutToBoundary (const Handle(Adaptor3d_HSurface)& theASurf1, const Handle(Adaptor3d_HSurface)& theASurf2);
   
@@ -208,7 +228,7 @@ private:
   Standard_Boolean close;
   Standard_Boolean tgfirst;
   Standard_Boolean tglast;
-  Standard_Integer indextg;
+  Standard_Integer myTangentIdx;
   gp_Dir tgdir;
   Standard_Real fleche;
   Standard_Real pasMax;
diff --git a/src/IntWalk/IntWalk_PWalking.lxx b/src/IntWalk/IntWalk_PWalking.lxx
index de3bd591c2..b9216b56f8 100644
--- a/src/IntWalk/IntWalk_PWalking.lxx
+++ b/src/IntWalk/IntWalk_PWalking.lxx
@@ -54,18 +54,16 @@ inline Standard_Boolean IntWalk_PWalking::IsClosed() const{
   return close;
 }
 
-inline const gp_Dir& IntWalk_PWalking::TangentAtLine
-  (Standard_Integer& Index) const
+inline const gp_Dir& IntWalk_PWalking::TangentAtLine(Standard_Integer& theIndex) const
 {
   if(!done) throw StdFail_NotDone();
-  Index = indextg;
+  theIndex = myTangentIdx;
   return tgdir;
 }
 
 #define REGLAGE 0
 
-inline void IntWalk_PWalking::AddAPoint(Handle(IntSurf_LineOn2S)& theLine,
-					const IntSurf_PntOn2S& POn2S) { 
+inline void IntWalk_PWalking::AddAPoint(const IntSurf_PntOn2S& POn2S) { 
 #if REGLAGE
   Standard_Integer n=theLine->NbPoints();
   if(n) { 
@@ -79,7 +77,8 @@ inline void IntWalk_PWalking::AddAPoint(Handle(IntSurf_LineOn2S)& theLine,
     fflush(stdout);
   }
 #endif
-  theLine->Add(POn2S);  
+  line->Add(POn2S);
+  myTangentIdx = Max(myTangentIdx, 1);
 }
 
 
diff --git a/tests/bugs/modalg_7/bug28764 b/tests/bugs/modalg_7/bug28764
new file mode 100644
index 0000000000..2609c4de63
--- /dev/null
+++ b/tests/bugs/modalg_7/bug28764
@@ -0,0 +1,24 @@
+puts "========"
+puts "OCC28764"
+puts "========"
+puts ""
+#################################################
+# [Regression to 7.0] Intersection of faces gives exception in debug mode
+#################################################
+
+restore [locate_data_file bug28764_ff.brep] f
+explode f
+
+####
+
+axo
+don f
+fit
+
+# Before the fix: Exception in Debug-mode only
+set log [bopcurves f_1 f_2 -2d]
+checkview -screenshot -2d -path ${imagedir}/${test_image}.png
+
+regexp {Tolerance Reached=+([-0-9.+eE]+)} ${log} full Toler
+checkreal TolReached $Toler 4.60347250530349e-008 0.0 0.1
+