Note that for index.vuh's the value of [ad_conn path_info] is always without a slash at the beginning. For a foo.vuh file it can either be an empty string (request for /foo directly), a single slash (request for /foo/) or more, with a beginning slash, e.g. /bar/baz for the request /foo/bar/baz.
This might be unexpected because it's different from index.vuh's, but I think it is the right behaviour because otherwise it would not be possible to distinguish if /foo or /foo/ was requested.
Anybody who has the time for some more testing?