I am using vista home with pdvd 3104, 2600xt and e6600cpu. I also use anydvd hd from slysoft. I have smooth playback of both blu-ray and hd-dvd (from hdd) with mpeg2, vc1, and h.264 avc. I am using the catalyst 7.11 drivers. In pdvd, hw acceleration stays enabled (checked). My cpu stays relatively low (5-20%) through all of the above types of movies. I am trying to validate whether on not hw accel. is actually working but with this combination I cannot seem to turn hw accel. off! I stop the movie, go into pdvd config, disable hw accel., save, then start the movie. When I go back into the config, hw accel is enabled! I have checked with ati's ccc which now has overdrive visible but grayed out. It show some gpu usage but not a lot (up to maybe 20%). I have played around with arcsoft on my xp partition (same machine that I dual-boot). With arcsoft, the vc1 encoded movies have a lot of judder. It doesn't seem like arcsoft is using hw accel. for the ati 2600xt but it does seem like pdvd is. Any suggestions on how to confirm this theory?