This looks like an old package. This problem was fixed some 3 months ago.
 Just installed RH7.1 with Value: "21.1 (patch 14)
\"Cuyahoga Valley\" XEmacs Lucid"
 
 Now ediff is broken.  Attempting an ediff gives:
 
 Can't diff remote file /tmp/....
 
 Of course I'm asking to diff local files.