Index: trunk/BNC/combination/bnccomb.cpp
===================================================================
--- trunk/BNC/combination/bnccomb.cpp	(revision 2935)
+++ trunk/BNC/combination/bnccomb.cpp	(revision 2936)
@@ -406,5 +406,7 @@
       pp->xx += dx(iPar);
       if (pp->type == cmbParam::clk) {
-        resCorr[pp->prn]->dClk = pp->xx / t_CST::c;
+        if (resCorr.find(pp->prn) != resCorr.end()) {
+          resCorr[pp->prn]->dClk = pp->xx / t_CST::c;
+        }
       }
     }