Index: trunk/psModules/src/imcombine/pmImageCombine.c
===================================================================
--- trunk/psModules/src/imcombine/pmImageCombine.c	(revision 21183)
+++ trunk/psModules/src/imcombine/pmImageCombine.c	(revision 23989)
@@ -132,4 +132,8 @@
         // Combine all the pixels, using the specified stat.
         if (!psVectorStats(stats, pixelData, pixelErrors, pixelMasks, 0xff)) {
+	    psError(PS_ERR_UNKNOWN, false, "failure to measure stats");
+	    return false;
+	}
+	if (isnan(stats->sampleMean)) {
             combine->data.F32[y][x] = NAN;
             psFree(buffer);
@@ -137,5 +141,5 @@
         }
         float combinedPixel = stats->sampleMean; // Value of the combination
-
+	
         if (iter == 0) {
             // Save the value produced with no rejection, since it may be useful later
@@ -364,5 +368,7 @@
     // Get the median
     psStats *stats = psStatsAlloc(PS_STAT_SAMPLE_MEDIAN);
-    psVectorStats(stats, pixels, NULL, mask, 1);
+    if (!psVectorStats(stats, pixels, NULL, mask, 1)) {
+	psError(PS_ERR_UNKNOWN, false, "failure to measure stats");
+    }
     float median = stats->sampleMedian;
     psFree(stats);