Index: /trunk/ppStack/src/ppStackCamera.c
===================================================================
--- /trunk/ppStack/src/ppStackCamera.c	(revision 17427)
+++ /trunk/ppStack/src/ppStackCamera.c	(revision 17428)
@@ -328,12 +328,14 @@
     // Sources for use as stamps
     bool status = false;                // Found the file?
-    pmFPAfile *sources = pmFPAfileDefineFromArgs(&status, config, "PPSTACK.SOURCES", "PPSTACK.SOURCES");
-    if (!status) {
-        psError(PS_ERR_IO, false, "Failed to load file definition PPSTACK.SOURCES");
-        return false;
-    }
-    if (sources && sources->type != PM_FPA_FILE_CMF) {
-        psError(PS_ERR_IO, true, "PPSTACK.SOURCES is not of type CMF");
-        return false;
+    if (havePSFs) {
+        pmFPAfile *sources = pmFPAfileDefineFromArgs(&status, config, "PPSTACK.SOURCES", "PPSTACK.SOURCES");
+        if (!status) {
+            psError(PS_ERR_IO, false, "Failed to load file definition PPSTACK.SOURCES");
+            return false;
+        }
+        if (sources && sources->type != PM_FPA_FILE_CMF) {
+            psError(PS_ERR_IO, true, "PPSTACK.SOURCES is not of type CMF");
+            return false;
+        }
     }
 
Index: /trunk/ppStack/src/ppStackMatch.c
===================================================================
--- /trunk/ppStack/src/ppStackMatch.c	(revision 17427)
+++ /trunk/ppStack/src/ppStackMatch.c	(revision 17428)
@@ -20,5 +20,4 @@
     assert(regions && !*regions);
     assert(kernels && !*kernels);
-    assert(sourcesRO);
     assert(config);
 
@@ -31,10 +30,15 @@
     bool mdok;                          // Status of MD lookup
     bool renorm = psMetadataLookupBool(&mdok, config->arguments, "RENORM"); // Renormalise variances?
-    psStatsOptions renormMean = psMetadataLookupS32(&mdok, config->arguments, "RENORM.MEAN"); // Statistic for mean
-    psStatsOptions renormStdev = psMetadataLookupS32(&mdok, config->arguments, "RENORM.STDEV"); // Statistic for stdev
-    int renormWidth = psMetadataLookupS32(&mdok, config->arguments, "RENORM.WIDTH"); // Width for renormalisation box
+    psStatsOptions renormMean = psMetadataLookupS32(&mdok, config->arguments,
+                                                    "RENORM.MEAN"); // Statistic for mean
+    psStatsOptions renormStdev = psMetadataLookupS32(&mdok, config->arguments,
+                                                     "RENORM.STDEV"); // Statistic for stdev
+    int renormWidth = psMetadataLookupS32(&mdok, config->arguments,
+                                          "RENORM.WIDTH"); // Width for renormalisation box
 
     if (psMetadataLookupBool(&mdok, config->arguments, "HAVE.PSF")) {
         assert(psf);
+        assert(sourcesRO);
+
         int order = psMetadataLookupS32(NULL, recipe, "SPATIAL.ORDER"); // Spatial polynomial order
         float regionSize = psMetadataLookupF32(NULL, recipe, "REGION.SIZE"); // Size of iso-kernel regs
@@ -44,6 +48,6 @@
         int iter = psMetadataLookupS32(NULL, recipe, "ITER"); // Rejection iterations
         float rej = psMetadataLookupF32(NULL, recipe, "REJ"); // Rejection threshold
-        pmSubtractionKernelsType type =
-            pmSubtractionKernelsTypeFromString(psMetadataLookupStr(NULL, recipe, "KERNEL.TYPE")); // Kernel type
+        pmSubtractionKernelsType type = pmSubtractionKernelsTypeFromString(
+            psMetadataLookupStr(NULL, recipe, "KERNEL.TYPE")); // Kernel type
         psVector *widths = psMetadataLookupPtr(NULL, recipe, "ISIS.WIDTHS"); // ISIS Gaussian widths
         psVector *orders = psMetadataLookupPtr(NULL, recipe, "ISIS.ORDERS"); // ISIS Polynomial orders
@@ -62,5 +66,5 @@
 
         // These values are specified specifically for stacking
-        const char *stampsName = psMetadataLookupStr(NULL, config->arguments, "STAMPS"); // Filename for stamps
+        const char *stampsName = psMetadataLookupStr(NULL, config->arguments, "STAMPS"); // Stamps filename
 
         psVector *optWidths = NULL;         // Vector with FWHMs for optimum search