diff --git a/TODO b/TODO
index 3f89f576..bdf9b20c 100644
--- a/TODO
+++ b/TODO
@@ -17,6 +17,8 @@ Policies:
 
 - Lanczos
 
+- Audit oIndex usage for cb behaviour
+
 - Rectangle gauge actions.
   Iwasaki,
   Symanzik,
diff --git a/lib/cartesian/Cartesian_base.h b/lib/cartesian/Cartesian_base.h
index 6303e38e..3b9f6630 100644
--- a/lib/cartesian/Cartesian_base.h
+++ b/lib/cartesian/Cartesian_base.h
@@ -166,8 +166,9 @@ public:
       pcoor.resize(_ndimension);
       lcoor.resize(_ndimension);
       for(int mu=0;mu<_ndimension;mu++){
-	pcoor[mu] = gcoor[mu]/_ldimensions[mu];
-	lcoor[mu] = gcoor[mu]%_ldimensions[mu];
+	int _fld  = _fdimensions[mu]/_processors[mu];
+	pcoor[mu] = gcoor[mu]/_fld;
+	lcoor[mu] = gcoor[mu]%_fld;
       }
     }
     void GlobalCoorToRankIndex(int &rank, int &o_idx, int &i_idx ,const std::vector<int> &gcoor)
@@ -176,8 +177,16 @@ public:
       std::vector<int> lcoor;
       GlobalCoorToProcessorCoorLocalCoor(pcoor,lcoor,gcoor);
       rank = RankFromProcessorCoor(pcoor);
-      i_idx= iIndex(lcoor);
-      o_idx= oIndex(lcoor);
+
+      std::vector<int> cblcoor(lcoor);
+      for(int d=0;d<cblcoor.size();d++){
+	if( this->CheckerBoarded(d) ) {
+	  cblcoor[d] = lcoor[d]/2;
+	}
+      }
+
+      i_idx= iIndex(cblcoor);// this does not imply divide by 2 on checker dim
+      o_idx= oIndex(lcoor);// this implies divide by 2 on checkerdim
     }
 
     void RankIndexToGlobalCoor(int rank, int o_idx, int i_idx , std::vector<int> &gcoor)
diff --git a/tests/Test_cshift_red_black.cc b/tests/Test_cshift_red_black.cc
index 88355e47..ed19a36a 100644
--- a/tests/Test_cshift_red_black.cc
+++ b/tests/Test_cshift_red_black.cc
@@ -53,6 +53,7 @@ int main (int argc, char ** argv)
 
 
   TComplex cm;
+  TComplex cmeo;
   for(int dir=0;dir<Nd;dir++){
     //    if ( dir!=1 ) continue;
     for(int shift=0;shift<latt_size[dir];shift++){
@@ -125,7 +126,17 @@ int main (int argc, char ** argv)
 	  
 	  peekSite(cm,rbShiftU,coor);
 
-	  double nrm=norm2(U);
+	  Integer checkerboard = RBFine.CheckerBoard(coor);
+
+	  //	  std::cout << " coor "<<" ["<<coor[0]<<","<<coor[1]<<","<<coor[2]<<","<<coor[3]<<"] \n ";
+	  //	  std::cout << "shift "<< shift <<" dir "<<dir<< " checker board "<< checkerboard << " ";
+	  //	  std::cout << "Uo "   << ShiftUo.checkerboard << " Ue "<<ShiftUe.checkerboard<<std::endl;
+	  if ( checkerboard == ShiftUo.checkerboard ) {
+	    peekSite(cmeo,ShiftUo,coor);
+	  } else { 
+	    peekSite(cmeo,ShiftUe,coor);
+	  }
+
 
 	  std::vector<int> scoor(coor);
 	  scoor[dir] = (scoor[dir]+shift)%latt_size[dir];
@@ -136,13 +147,29 @@ int main (int argc, char ** argv)
 	    + latt_size[0]*latt_size[1]*latt_size[2]*scoor[3];
 
 	  Complex scm(slex);
-	  
-	  nrm = abs(scm-cm()()());
+
 	  std::vector<int> peer(4);
-	  Complex ctmp=cm;
+	  Complex ctmp=cmeo;
 	  Integer index=real(ctmp);
 	  Fine.CoorFromIndex(peer,index,latt_size);
 
+	  double nrm = abs(cmeo()()()-scm);
+	  if (nrm != 0) {
+	    std::cout<<"EOFAIL shift "<< shift<<" in dir "<< dir
+		     <<" ["<<coor[0]<<","<<coor[1]<<","<<coor[2]<<","<<coor[3]<<"] = "
+		     << cmeo()()()<<" expect "<<scm<<"  "<<nrm<<std::endl;
+	    std::cout<<"Got    "<<index<<" " << peer[0]<<","<<peer[1]<<","<<peer[2]<<","<<peer[3]<<std::endl;
+	    index=real(scm);
+	    Fine.CoorFromIndex(peer,index,latt_size);
+	    std::cout<<"Expect "<<index<<" " << peer[0]<<","<<peer[1]<<","<<peer[2]<<","<<peer[3]<<std::endl;
+	    exx=1;
+
+	  }
+
+	  ctmp=cm;
+	  index=real(ctmp);
+	  nrm = abs(scm-cm()()());
+
 	  if (nrm > 0){
 	    std::cout<<"FAIL shift "<< shift<<" in dir "<< dir
 		     <<" ["<<coor[0]<<","<<coor[1]<<","<<coor[2]<<","<<coor[3]<<"] = "