I can run the game perfectly (most of the time) with mediavps and all the settings up. However, sometimes it's like my screen stops refereshing for anywhere from half a second to a second and a half, ie nothing on the screen changes, but once it wakes back up things have moved like you'd expect them to; it's not like it momentarily froze. At first I figured it was something to do with crossing an arbitrary line and the game pausing to load another area or something, but it happens in dogfights when I'm not really covering that much space as well as when I'm going from one objective to another, so that doesn't seem to be it.
I have GMA 950, which is crap, but like I said it ordinarily handles the game just fine, I also have 2GB of memory and a T2300, I've set the game process affinity to CPU 0, and that core is always loaded 100% when playing. I know GMA 950 offloads some things to the CPU, like Texture and Lighting, but I think if this was a hardware problem it would be happening more frequently, right now it's mostly an intermittent problem.
Also, it does this when playing FS2 and FSPort, if that makes any difference.