I installed 2.55 but did not like-i got the PwerDVD CD bundled with another card, SIIG Aurora. Cinemaster 2000 plays better but since I also have Hollywood Plus in the system, I used the beta player for hollywood plus instead. The cpu load is much lower since it utilizes the card for DVD playback.
The driver for AIW that I'm using is the one from the Win2K Server CD. I noticed that ATI now has a special purposed driver and video tool in their website but I didn't bother to update mine since I'm happy with the playback and TV output. I'v been using Video Studio 4.0 for capturing and editing video since February, no ATI player yet for Windows 2000 at that time.