I have just finished building my first HTPC using a Gigabyte MA790GP-UD4H and Phenom II 720 with Vista Home Premium x64 and 4GB of DDR-800. The picture and sound are great for the most part (using onboard HDMI out to a Samsung LN46A550), but there is a definite stutter going on with both the picture and sound when playing BDs using Arcsoft TotalMedia. I noticed in the vista resource monitor that there is a disc spike occurring when these slight stutters happen. I have updated to catalyst 9.3 (from the initial install of 8.12) and that seems to have helped a bit, but the problem is still definitely there. Any ideas?