Index: trunk/ppMerge/src/ppMergeLoop.c
===================================================================
--- trunk/ppMerge/src/ppMergeLoop.c	(revision 25769)
+++ trunk/ppMerge/src/ppMergeLoop.c	(revision 33093)
@@ -382,5 +382,5 @@
 
             // Wait for the threads to finish and manage results
-            if (!psThreadPoolWait(false)) {
+            if (!psThreadPoolWait(false, true)) {
                 psError(PS_ERR_UNKNOWN, false, "Unable to combine images.");
                 return false;