Index: trunk/ippTools/share/difftool_skyfile.sql
===================================================================
--- trunk/ippTools/share/difftool_skyfile.sql	(revision 21019)
+++ trunk/ippTools/share/difftool_skyfile.sql	(revision 21088)
@@ -11,5 +11,5 @@
     USING(diff_id)
 JOIN diffInputSkyfile
-    ON diffInputSkyfile.diff_id = diffRun.diff_id
+    USING (diff_id, skycell_id)
 JOIN warpRun
     ON warpRun.warp_id = diffInputSkyfile.warp1