Regardless of the URL confusion, you shouldn't have had to change X Mosaic
or the cern_httpd. URLs of the form file://host.domain/ are interpreted by
Cello, Lynx, Mosaic, etc. as ftp URLs, so the proxying still works
correctly. URLs of the form file://localhost/ are considered local
filesystem references.
Yes, use of file: rather than ftp: is rather confusing. It is the job of
the URI working group to document correct URL usage, but it will be
sometime before people can be persuaded not to use file: instead of ftp:.
ka