Index: trunk/psModules/src/imcombine/pmSubtractionParams.c
===================================================================
--- trunk/psModules/src/imcombine/pmSubtractionParams.c	(revision 14716)
+++ trunk/psModules/src/imcombine/pmSubtractionParams.c	(revision 14719)
@@ -307,4 +307,14 @@
         bestChi2 /= numPixels;
 
+        if (bestIndex == -1) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to find best kernel component in round %d.", iter);
+            psFree(inputs);
+            psFree(sumC);
+            psFree(sumCC);
+            psFree(ranking);
+            psFree(kernels);
+            return NULL;
+        }
+
         // And the winner is....
         ranking->data.S32[bestIndex] = iter;