Index: trunk/psModules/src/imcombine/pmSubtractionMatch.c
===================================================================
--- trunk/psModules/src/imcombine/pmSubtractionMatch.c	(revision 23577)
+++ trunk/psModules/src/imcombine/pmSubtractionMatch.c	(revision 23688)
@@ -18,6 +18,8 @@
 #include "pmSubtractionMask.h"
 #include "pmSubtractionThreads.h"
+#include "pmSubtractionVisual.h"
+#include "pmErrorCodes.h"
+
 #include "pmSubtractionMatch.h"
-#include "pmSubtractionVisual.h"
 
 #define BG_STAT PS_STAT_ROBUST_MEDIAN   // Statistic to use for background
@@ -73,5 +75,5 @@
                                       stampSpacing, mode);
     if (!*stamps) {
-        psError(PS_ERR_UNKNOWN, false, "Unable to find stamps.");
+        psError(psErrorCodeLast(), false, "Unable to find stamps.");
         return false;
     }
Index: trunk/psModules/src/imcombine/pmSubtractionStamps.c
===================================================================
--- trunk/psModules/src/imcombine/pmSubtractionStamps.c	(revision 23577)
+++ trunk/psModules/src/imcombine/pmSubtractionStamps.c	(revision 23688)
@@ -20,5 +20,5 @@
 #include "pmModel.h"
 #include "pmSource.h"
-
+#include "pmErrorCodes.h"
 
 #include "pmSubtraction.h"
@@ -355,4 +355,5 @@
     if (numGood == 0 && numFound == 0) {
         // No good stamps
+        psError(PM_ERR_STAMPS, true, "Unable to find suitable stamps");
         psFree(stamps);
         return NULL;