Index: /trunk/psModules/src/imcombine/pmSubtractionMatch.c
===================================================================
--- /trunk/psModules/src/imcombine/pmSubtractionMatch.c	(revision 14603)
+++ /trunk/psModules/src/imcombine/pmSubtractionMatch.c	(revision 14604)
@@ -148,5 +148,5 @@
     pmSubtractionKernels *kernels = pmSubtractionKernelsGenerate(type, size, order, isisWidths, isisOrders,
                                                                  inner, binning, ringsOrder);
-    psMetadataAddPtr(convolved->analysis, PS_LIST_TAIL, "SUBTRACTION.KERNEL", 0,
+    psMetadataAddPtr(convolved->analysis, PS_LIST_TAIL, "SUBTRACTION.KERNEL", PS_DATA_UNKNOWN,
                      "Subtraction kernels", kernels);
     psArray *stamps = NULL;             // Stamps for matching PSF
@@ -220,4 +220,9 @@
                 memCheck("  find stamps");
 
+                if (!input && !pmSubtractionGenerateStamps(stamps, targetWidth, footprint, kernels)) {
+                    psError(PS_ERR_UNKNOWN, false, "Unable to generate target stamps.");
+                    goto ERROR;
+                }
+
                 psTrace("psModules.imcombine", 3, "Extracting stamps...\n");
                 if (!pmSubtractionExtractStamps(stamps, reference->image, inImage, weight,