Index: trunk/ppStack/src/ppStackMatch.c
===================================================================
--- trunk/ppStack/src/ppStackMatch.c	(revision 17426)
+++ 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