Problems with svn diff --old=<file URL>

   I'm trying to compare a tagged file to the version in my WC and
getting this error:

[pucca:Foo/Foo/build] wsanchez% svn diff
--old=http://foo.apple.com/svn/tags/x/build/dobuild dobuild
subversion/libsvn_ra_dav/util.c:670: (apr_err=175002)
svn: PROPFIND request failed on '/svn/tags/x/build/dobuild/dobuild'
subversion/libsvn_ra_dav/util.c:294: (apr_err=175002)
svn: PROPFIND of '/svn/tags/x/build/dobuild/dobuild': 500 Internal
Server Error (http://foo.apple.com)

   From the httpd log:

[Tue Jan 11 14:07:24 2005] [error] [client 17.216.16.189] Could not
fetch resource information. [500, #0]
[Tue Jan 11 14:07:24 2005] [error] [client 17.216.16.189] Error
checking kind of path '/tags/x/build/dobuild/dobuild' in repository
[500, #160016]
[Tue Jan 11 14:07:24 2005] [error] [client 17.216.16.189] Failure
opening '/tags/x/build/dobuild/dobuild' [500, #160016]

   What's up with that? I can list the tagged file just fine:

[pucca: Foo/Foo/build] wsanchez% svn ls -v
http://foo.apple.com/svn/tags/x/build/dobuild
   24635 dude 15147 Dec 20 19:01 dobuild

   Is something wrong with the repository?

     -wsv