Index: trunk/ppSub/src/ppSubReadout.c
===================================================================
--- trunk/ppSub/src/ppSubReadout.c	(revision 19687)
+++ trunk/ppSub/src/ppSubReadout.c	(revision 19691)
@@ -249,5 +249,5 @@
         psStats *vfStats = psStatsAlloc(PS_STAT_ROBUST_MEDIAN); // Statistics
         psRandom *rng = psRandomAlloc(PS_RANDOM_TAUS, 0); // Random number generator
-        if (!psImageBackground(vfStats, NULL, inConv->weight, inConv->mask, maskVal | maskBad, NULL)) {
+        if (!psImageBackground(vfStats, NULL, inConv->weight, inConv->mask, maskVal | maskBad, rng)) {
             psError(PS_ERR_UNKNOWN, false, "Unable to measure mean variance for convolved input");
             psFree(inConv);
@@ -255,8 +255,9 @@
             psFree(outRO);
             psFree(vfStats);
+            psFree(rng);
             return false;
         }
         float inMeanVar = vfStats->robustMedian; // Mean variance of input
-        if (!psImageBackground(vfStats, NULL, refConv->weight, refConv->mask, maskVal | maskBad, NULL)) {
+        if (!psImageBackground(vfStats, NULL, refConv->weight, refConv->mask, maskVal | maskBad, rng)) {
             psError(PS_ERR_UNKNOWN, false, "Unable to measure mean variance for convolved reference");
             psFree(inConv);
@@ -264,4 +265,5 @@
             psFree(outRO);
             psFree(vfStats);
+            psFree(rng);
             return false;
         }