Index: trunk/Ohana/src/dvomerge/src/dvo_image_merge_dbs.c
===================================================================
--- trunk/Ohana/src/dvomerge/src/dvo_image_merge_dbs.c	(revision 36528)
+++ trunk/Ohana/src/dvomerge/src/dvo_image_merge_dbs.c	(revision 36833)
@@ -168,4 +168,9 @@
 
   if (!IDmap->old) {
+    fprintf (stderr, "input database has image IDs, but no Image table\n");
+    return FALSE;
+  }
+
+  if (!IDmap->Nmap) {
     fprintf (stderr, "input database has image IDs, but no Image table\n");
     return FALSE;
Index: trunk/Ohana/src/dvomerge/src/dvomergeImageIDs.c
===================================================================
--- trunk/Ohana/src/dvomerge/src/dvomergeImageIDs.c	(revision 36528)
+++ trunk/Ohana/src/dvomerge/src/dvomergeImageIDs.c	(revision 36833)
@@ -18,4 +18,6 @@
   if (inDB.dbstate == LCK_EMPTY) {
     dvo_image_unlock (&inDB); // unlock input
+    IDmap->old = NULL;
+    IDmap->new = NULL;
     IDmap->Nmap = 0;
     return TRUE;
@@ -99,4 +101,6 @@
   if (inDB.dbstate == LCK_EMPTY) {
     dvo_image_unlock (&inDB); // unlock input
+    IDmap->old = NULL;
+    IDmap->new = NULL;
     IDmap->Nmap = 0;
     return TRUE;
Index: trunk/Ohana/src/dvomerge/src/dvorepairCPT.c
===================================================================
--- trunk/Ohana/src/dvomerge/src/dvorepairCPT.c	(revision 36528)
+++ trunk/Ohana/src/dvomerge/src/dvorepairCPT.c	(revision 36833)
@@ -126,5 +126,5 @@
     average[Nave].measureOffset = -1;
     average[Nave].missingOffset = -1;
-    average[Nave].extendOffset = -1;
+    average[Nave].refColor = NAN;
 
     average[Nave].objID = measure[i].objID;
Index: trunk/Ohana/src/dvomerge/src/dvorepairDeleteImageList.c
===================================================================
--- trunk/Ohana/src/dvomerge/src/dvorepairDeleteImageList.c	(revision 36528)
+++ trunk/Ohana/src/dvomerge/src/dvorepairDeleteImageList.c	(revision 36833)
@@ -411,5 +411,5 @@
     average[Nave].measureOffset = -1;
     average[Nave].missingOffset = -1;
-    average[Nave].extendOffset = -1;
+    average[Nave].refColor = NAN;
 
     average[Nave].objID = measure[i].objID;
Index: trunk/Ohana/src/dvomerge/src/dvorepairFixTables.c
===================================================================
--- trunk/Ohana/src/dvomerge/src/dvorepairFixTables.c	(revision 36528)
+++ trunk/Ohana/src/dvomerge/src/dvorepairFixTables.c	(revision 36833)
@@ -266,5 +266,5 @@
     average[Nave].measureOffset = -1;
     average[Nave].missingOffset = -1;
-    average[Nave].extendOffset = -1;
+    average[Nave].refColor = NAN;
 
     average[Nave].objID = measure[i].objID;