I'm having the EXACT same problem. I noticed it because I use [tab] frequently, and all the text that displays appears to cripple the game, to the point where the mouse will move in 3 or 4 inch jerks. I'm running in Vista 32-bit with 2GB of RAM, 2.4GHz T7700, with latest sound and video drivers. While I'm playing there's a good 512mb of free RAM, and A4 is maxing out one of the cores, and using between 10-20% of the second one. I would say that it was a dual-core compatibility problem, but even one of my cores is more powerful than the PM I used to play A4 on, which ran without a hitch.