diff --git a/SurfBezier.cpp b/SurfBezier.cpp
index 29a47b1..c9fea9a 100644
--- a/SurfBezier.cpp
+++ b/SurfBezier.cpp
@@ -5988,7 +5988,9 @@ SurfBezier::CreateByIsoParamSet( const ICurve* pCurve0, const ICurve* pCurve1, c
       double dFloor0 = floor( dNewStart0) ;
       double dCeil1 = ceil( dNewStart1) ;
       double dFloor1 = floor( dNewStart1) ;
+      vPnt0.pop_back() ;
       rotate( vPnt0.begin(), vPnt0.begin() + int( dCeil0), vPnt0.end()) ;
+      vPnt1.pop_back() ;
       rotate( vPnt1.begin(), vPnt1.begin() + int( dCeil1), vPnt1.end()) ;
       if ( abs( dNewStart0 - round( dNewStart0)) > EPS_SMALL) {
          Point3d ptNewStart ; CrvU0.GetStartPoint( ptNewStart) ;
@@ -6125,7 +6127,7 @@ SurfBezier::CreateByIsoParamSet( const ICurve* pCurve0, const ICurve* pCurve1, c
                return false ;
             }
             // se ho una corrispondenza tra punti ( e non sono alla fine del tratto) allora non aggiungo split
-            if ( abs( vdParamPos0[c0] - vdParamPos1[c1]) < EPS_PARAM  &&  vdParamPos0[c0] < 1) {
+            if ( abs( vdParamPos0[c0] - vdParamPos1[c1]) < EPS_SMALL  &&  vdParamPos0[c0] < 1) {
                ++c0 ;
                ++c1 ;
                ++nLastParam0 ;
@@ -6140,6 +6142,7 @@ SurfBezier::CreateByIsoParamSet( const ICurve* pCurve0, const ICurve* pCurve1, c
                   nSplit1 = vdSplit1.size() ;
                }
                else if ( dPar = round( dPar) ;  dPar > nLastParam1){
+                  ++ c1 ;
                   ++ nLastParam1 ;
                }
                ++nLastParam0 ;
@@ -6154,6 +6157,7 @@ SurfBezier::CreateByIsoParamSet( const ICurve* pCurve0, const ICurve* pCurve1, c
                   nSplit0 = vdSplit0.size() ;
                }
                else if ( dPar = round( dPar) ;  dPar > nLastParam0){
+                  ++ c0 ;
                   ++ nLastParam0 ;
                }
                ++nLastParam1 ;