Can't Access Media Files on Windows 7 PC

I bought a Live Hub Media Player yesterday and am having problems accessing my main PC where most of my media files are stored.  When I go to “Select Content Source - Media Server” and select that PC it shows Videos: Folders: and tries to load but shows the message “The last content source has been removed.  Please select a new content source.”   This PC is running Windows 7 and I have media sharing set up with Windows Media Player and I can access the media files on this PC with my PS3 and also the Mediagate media player I was using until it stopped working this week and I bought the Live Hub.   I have tried accessing the files both through the Video and Files menus on the Hub with the same error message. 

I can access files on other PCs on the network - Windows 7 PCs set up with media sharing with Windows Media Player as well as XP PCs running Twonky and it also plays files copied to its internal drive without any problems.

I would appreciate any suggestions on how to get the Live Hub to play files from this PC.

Did you ever resolved this issue?