Index: branches/eam_branches/relastro.20100326/src/UpdateChips.c
===================================================================
--- branches/eam_branches/relastro.20100326/src/UpdateChips.c	(revision 27490)
+++ branches/eam_branches/relastro.20100326/src/UpdateChips.c	(revision 27497)
@@ -18,7 +18,9 @@
     /* convert measure coordinates to raw entries */
     raw = getImageRaw (catalog, Ncatalog, i, &Nraw, MODE_MOSAIC);
+    if (!raw) continue;
 
     /* convert average coordinates to ref entries */
     ref = getImageRef (catalog, Ncatalog, i, &Nref, MODE_MOSAIC);
+    if (!ref) continue;
 
     // note that Nraw & Nref must be equal: if not, we made a programming error in one of these two functions.