Index: branches/pap/ppStack/src/ppStackThread.c
===================================================================
--- branches/pap/ppStack/src/ppStackThread.c	(revision 23948)
+++ branches/pap/ppStack/src/ppStackThread.c	(revision 25027)
@@ -187,8 +187,9 @@
 
 
+		int zMax = 0;
                 bool keepReading = false;
-                if (pmReadoutMore(ro, imageFits, 0, rows, config)) {
+                if (pmReadoutMore(ro, imageFits, 0, &zMax, rows, config)) {
                     keepReading = true;
-                    if (!pmReadoutReadChunk(ro, imageFits, 0, rows, overlap, config)) {
+                    if (!pmReadoutReadChunk(ro, imageFits, 0, NULL, rows, overlap, config)) {
                         psError(PS_ERR_IO, false, "Unable to read chunk %d for file PPSTACK.INPUT %d",
                                 numChunk, i);
@@ -198,7 +199,7 @@
                 }
 
-                if (pmReadoutMoreMask(ro, maskFits, 0, rows, config)) {
+                if (pmReadoutMoreMask(ro, maskFits, 0, &zMax, rows, config)) {
                     keepReading = true;
-                    if (!pmReadoutReadChunkMask(ro, maskFits, 0, rows, overlap, config)) {
+                    if (!pmReadoutReadChunkMask(ro, maskFits, 0, NULL, rows, overlap, config)) {
                         psError(PS_ERR_IO, false, "Unable to read chunk %d for file PPSTACK.INPUT.MASK %d",
                                 numChunk, i);
@@ -208,7 +209,7 @@
                 }
 
-                if (pmReadoutMoreVariance(ro, varianceFits, 0, rows, config)) {
+                if (pmReadoutMoreVariance(ro, varianceFits, 0, &zMax, rows, config)) {
                     keepReading = true;
-                    if (!pmReadoutReadChunkVariance(ro, varianceFits, 0, rows, overlap, config)) {
+                    if (!pmReadoutReadChunkVariance(ro, varianceFits, 0, NULL, rows, overlap, config)) {
                         psError(PS_ERR_IO, false,
                                 "Unable to read chunk %d for file PPSTACK.INPUT.VARIANCE %d",