FSX SP2/Accel won't run with Win 7 x64

Hi folks. I wonder if anyone is seeing the same problem as me.I've installed Windows 7 x64 and it is running fine.Initial install of FSX runs fine. As does the sim once SP1 is installed.But if I install SP2 or the Accleration pack (I've tried both - on clean FSX + SP1 installs) then the game will not work. The splash screen appears. And remains for the usual loading time. Then the plash screen disappears, windows switches back to full color mode and that's that. No error message, the game just won't run.