Index: /trunk/ppMerge/src/ppMergeMask.c
===================================================================
--- /trunk/ppMerge/src/ppMergeMask.c	(revision 15652)
+++ /trunk/ppMerge/src/ppMergeMask.c	(revision 15653)
@@ -92,4 +92,5 @@
     while ((chipOut = pmFPAviewNextChip(view, fpaOut, 1))) {
         if (chipOut->hdu) {
+            chipOut->data_exists = true;
             pmFPAUpdateNames(fpaOut, chipOut, NULL);
         }
@@ -98,4 +99,5 @@
         while ((cellOut = pmFPAviewNextCell(view, fpaOut, 1))) {
             if (cellOut->hdu) {
+                chipOut->data_exists = cellOut->data_exists = true;
                 pmFPAUpdateNames(fpaOut, chipOut, cellOut);
             }