Index: trunk/ppStack/src/ppStackSources.c
===================================================================
--- trunk/ppStack/src/ppStackSources.c	(revision 20940)
+++ trunk/ppStack/src/ppStackSources.c	(revision 20944)
@@ -208,5 +208,5 @@
 
     if (bounds->x0 > list->bounds->x1 || bounds->x1 < list->bounds->x0 ||
-        bounds->x0 > list->bounds->x1 || bounds->x1 < list->bounds->x0) {
+        bounds->y0 > list->bounds->y1 || bounds->y1 < list->bounds->y0) {
         // Bounds don't overlap, so the sources don't either
         psTrace("ppStack.sources", 7, "Bounds don't overlap\n");