Unable to connect to Windows Vista Ultimate PC

[bdipert]

Apologies for what is perhaps an elementary question; I'm a new HD200 owner. I have a Dell XPS-M1330 laptop running Windows Vista Ultimate, with an ATSC add-in ExpressCard used for over-the-air recording and live television viewing through Windows Media Center (i.e. I'm attempting to use the HD200 in standalone mode, not with the SageTV software). That same laptop is also running MediaMall Technologies' PlayOn.

The good news is that I'm able to stream Hulu and other content to the HD200 just fine using PlayOn, which appears as a UPnP candidate in the Filesystems listing. I'm also able to 'see' and access the XPS-M1330's Windows Media Player UPnP server, as well as the UPnP server software running on my two NASs (TwonkyMedia, built into a Linksys NAS200 and added to a NETGEAR ReadyNAS).

The bad news is that I can't figure out how to 'see' the Recorded TV folder on the XPS-M1330, therefore can't play back DVR-MS formatted recorded shows from it. The exact folder location is c:/users/public/recorded tv. The guest account is enabled on the system, and 'public' file sharing is active (and password-unprotected as well). I explicitly gave 'everyone' read-only shared access to the 'recorded tv' folder. My Macs can access that folder just fine, so I know it's 'open'.

The Macs and Windows systems can all 'see' the HD200, named 'stp-hd200', so I know I've correctly configured its workgroup setting. But when I go into the HD200's Filesystems menu option, then 'Browse the local network', all I get back is 'Invalid directory'. This is probably just something obvious I'm overlooking, so patient guidance from y'all is greatly appreciated. Thanks in advance!

By the way, I'm running the latest beta firmware, which thankfully has a much 'snappier' UI than the latest production version. But it hasn't solved this particular problem.