Index: trunk/psphot/src/psphotGuessModels.c
===================================================================
--- trunk/psphot/src/psphotGuessModels.c	(revision 32996)
+++ trunk/psphot/src/psphotGuessModels.c	(revision 33089)
@@ -112,5 +112,7 @@
         // wait here for the threaded jobs to finish
         // fprintf (stderr, "wait for threads (%d, %d)\n", jx, jy);
-        if (!psThreadPoolWait (false)) {
+        if (!psThreadPoolWait (false, true)) {
+            // harvest our jobs
+            psFree(cellGroups);
             psError(PS_ERR_UNKNOWN, false, "Unable to guess model.");
             return false;