Index: branches/pap/ppStack/src/ppStackThread.c
===================================================================
--- branches/pap/ppStack/src/ppStackThread.c	(revision 25788)
+++ branches/pap/ppStack/src/ppStackThread.c	(revision 25799)
@@ -91,10 +91,10 @@
 
 // Open an image
-#define IMAGE_OPEN(NAME, FITS) \
-        if (NAME) { \
-            psString resolved = pmConfigConvertFilename(NAME, config, false, false); \
-            FITS = psFitsOpen(resolved, "r"); \
-            if (!(FITS)) { \
-                psError(PS_ERR_IO, false, "Unable to open file %s", (char*)(NAME)); \
+#define IMAGE_OPEN(NAMES, FITS, INDEX)          \
+        if (NAMES) { \
+            psString resolved = pmConfigConvertFilename((NAMES)->data[INDEX], config, false, false); \
+            (FITS)->data[INDEX] = psFitsOpen(resolved, "r");                            \
+            if (!(FITS)->data[INDEX]) { \
+                psError(PS_ERR_IO, false, "Unable to open file %s", (char*)(NAMES)->data[INDEX]); \
                 psFree(resolved); \
                 return NULL; \
@@ -103,7 +103,7 @@
         }
 
-        IMAGE_OPEN(imageNames->data[i], stack->imageFits->data[i]);
-        IMAGE_OPEN(maskNames->data[i], stack->maskFits->data[i]);
-        IMAGE_OPEN(varianceNames->data[i], stack->varianceFits->data[i]);
+        IMAGE_OPEN(imageNames, stack->imageFits, i);
+        IMAGE_OPEN(maskNames, stack->maskFits, i);
+        IMAGE_OPEN(varianceNames, stack->varianceFits, i);
     }