Index: trunk/ippScripts/scripts/diff_skycell.pl
===================================================================
--- trunk/ippScripts/scripts/diff_skycell.pl	(revision 26567)
+++ trunk/ippScripts/scripts/diff_skycell.pl	(revision 26568)
@@ -254,5 +254,7 @@
     $command .= " -F PSPHOT.OUTPUT PSPHOT.OUT.CMF.MEF";
     $command .= " -F PSPHOT.BACKMDL PSPHOT.BACKMDL.MEF";
-    $command .= " -photometry";
+    if ($run_state eq "new") {
+        $command .= " -photometry";
+    }
     $command .= " -inverse" if $inverse;
     $command .= " -tracedest $traceDest -log $logDest";
@@ -322,5 +324,5 @@
         unless ($success) {
             $error_code = (($error_code >> 8) or $PS_EXIT_PROG_ERROR);
-            my $err_message = $run_state eq "update" ? 
+            my $err_message = $run_state eq "update" ?
                 "Unable to perform difftool -adddiffskyfile" :
                 "Unable to perform difftool -tofullskyfile";