CTD on Windows Vista

Hi,I have a Dell Inspiron, 2gb ram, dual core Turion Mobile processor, ati x1240 video.I get CTD's and FSX restarts when doing any of the following things:1. Loading a saved game file (saved flight from the flight planner).2. Changing any settings while in flight (weather, resolution, scenery detail, etc)3. When I crash whatever i'm flying and FSX tries to restart the flight.4. If I set the sim speed to a high setting for a while...then go back to regular 1x.5. Failing a mission.In short anything that makes FSX reload scenery and traffic while in flight. I have Windows Vista. I have tried updating vista to SP1 RC, I have updated FSX to SP2. None of that works. I have rolled Vista back to pre SP1 RC and uninstalled SP2 from FSX. I have the most current drivers. Running an integrated ATI card by the way as I know there have been issues with some nVidia cards/drivers.Please help and thanks!