On a WSS site I created a DVWP from a document library web part and
it works fine for users who have permissions to that library.
However, when a user that does not have permission to the library
tries to access the site they get an "Access denied. You do not have
permission to perform this action or access this resource" error for
the entire site (they can't access the site), just like they don't
have permissions to the site.

Using just a regular Document Library web part, the same user would
have access to the site, but under that specific web part they would
get the same error message ("Access denied. You do not have
permission to perform this action or access this resource").

Why does the DVWP handle this differently and is there a way to fix
this? I tried looking through the XSL source, but didn't see
anything relevant there.