Index: trunk/psModules/src/imcombine/pmSubtractionEquation.c
===================================================================
--- trunk/psModules/src/imcombine/pmSubtractionEquation.c	(revision 30622)
+++ trunk/psModules/src/imcombine/pmSubtractionEquation.c	(revision 33089)
@@ -958,5 +958,5 @@
     }
 
-    if (!psThreadPoolWait(true)) {
+    if (!psThreadPoolWait(true, true)) {
         psError(psErrorCodeLast(), false, "Error waiting for threads.");
         return false;