Index: trunk/psModules/src/imcombine/pmReadoutCombine.c
===================================================================
--- trunk/psModules/src/imcombine/pmReadoutCombine.c	(revision 12696)
+++ trunk/psModules/src/imcombine/pmReadoutCombine.c	(revision 13591)
@@ -29,4 +29,5 @@
     params->combine = combine;
     params->maskVal = 0;
+    params->blank = 0;
     params->nKeep = 0;
     params->fracHigh = 0.0;
@@ -335,5 +336,5 @@
 
             if (numValid == 0) {
-                outputMask[yOut][xOut] = PM_MASK_FLAT;
+                outputMask[yOut][xOut] = params->blank;
                 outputImage[yOut][xOut] = NAN;
                 continue;