When I'm flying, sometimes (not always), when I'm on VC, the game stops, and after some time, a screen saying "A fatal error has ocurred", with the MS Error Report style, but I've seen to figure that this happens ONLY on Accel. new planes. It's not hardware related as I've just confirmed it.
Also, when I exit FSX, by the Main Menu, or In-Flight, the process stays on, occupying up to 500megs of memory.
These errors started just after I installed Acceleration.