Hi FRX,
I've just managed to get a DVR system working on my new Vista platform.
I'm using a "Digital Network security system" DVR card.
This is recognised in my Sound, Video and Game Contoller area as a Conexant's BtPCI WDM Video Capture card, using a BT848.sys driver file.
The capture software is Active WebCam 8.5, and without too much fuss, I am now recording 2 camera inputs to my hard drive.
I opted to install everything in Xp compatability mode, and it all seems OK so far.