Index: branches/pap/psModules/src/astrom/pmAstrometryWCS.c
===================================================================
--- branches/pap/psModules/src/astrom/pmAstrometryWCS.c	(revision 23948)
+++ branches/pap/psModules/src/astrom/pmAstrometryWCS.c	(revision 25027)
@@ -96,4 +96,9 @@
 
     if (!status1 || !status2) {
+        Nx = psMetadataLookupS32 (&status1, header, "IMNAXIS1");
+        Ny = psMetadataLookupS32 (&status2, header, "IMNAXIS2");
+    }
+
+    if (!status1 || !status2) {
         Nx = psMetadataLookupS32 (&status1, header, "ZNAXIS1");
         Ny = psMetadataLookupS32 (&status2, header, "ZNAXIS2");
@@ -143,6 +148,6 @@
     int Nx = region->x1 - region->x0;
     int Ny = region->y1 - region->y0;
-    psMetadataAddS32 (header, PS_LIST_TAIL, "NAXIS1", PS_META_REPLACE, "Mosaic Dimensions", Nx);
-    psMetadataAddS32 (header, PS_LIST_TAIL, "NAXIS2", PS_META_REPLACE, "Mosaic Dimensions", Ny);
+    psMetadataAddS32 (header, PS_LIST_TAIL, "IMNAXIS1", PS_META_REPLACE, "Mosaic Dimensions", Nx);
+    psMetadataAddS32 (header, PS_LIST_TAIL, "IMNAXIS2", PS_META_REPLACE, "Mosaic Dimensions", Ny);
 
     pmAstromWCStoHeader (header, wcs);