In this case, it seems reasonable to believe the evidence of your own eyes,
interpret the provider's statement as "when we tried it, we could not get it
to work", then try to determine what differences there might be between your
configuration and theirs, or, depending on what you need to do, determine
what makes your configuration how to work.

e.g. they may be using a different version of Server 2003 (not SBS), a
different version of the MDAC or Jet, etc. I would also want to be sure that
they were talking about regular shares or DFS shares. However, where servers
are being used the chances are that there is something different about the
security environment, e.g.do the users have the necessary rights to the
file(s), the folders, and the share?

Peter Jamieson