Oh boy. This could take a little while to figure out...
Sounds like your installed cards are inactive. Try activating your chosen or all cards.
Using a member created Player Manager is useful for playing demo clips in Fullscreen and Desktop mode. Once installed on your computer, the demos can be accessed thru these Player Managers :)
You have to bear in mind that the member created managers allow you to select ANY clip on your drive but they STILL only play thru the original VG software. By that, I mean they will let you select whatever you want but if your collection is disabled in the VG GUI, then maybe no cards will play?
Did that help?