I've searched on the forums for someone with a similar problem, but it appears no one has had this experience (or has yet to come out of the shadows).
First, the basic system parameters:
FSX with SP2 (not Acceleration)
Windows Vista Ultimate x64
Intel Q6600, OCed to 3.0GHz with a Thermaltake V1 cooler
abit IP35 Pro with latest BIOS and drivers
4GB of G.SKILL RAM (2x2GB)
Western Digital Raptor 10KRPM 150GB
evga 8800GTX (768MB) with 169 series driver
Thermaltake 700W PSU
Lian Li PC61 case (2 front fans, 1 rear fan, 1 blowhole fan)
The problem: Every now and then, FSX will freeze up. The audio will keep streaming (say, engines running), but the video image will become static. Task Manager reports FSX is not responding. This always happens during IFR flight, and except for one occasion always during an ILS approach (one occasion was during climbout). I previously ran the same copy of FSX on an hp computer with all sliders at minimum with no such problem. I have tried running with minimum sliders on the current computer - same crash.
I ran RivaTuner and the Windows diagnostics; attached are three screenshots (immedeately upon crash, after forcing FSX to exit through task manager, and after 10 minutes of idle - no programs save RivaTuner and Task Manager). The numbers for RivaTuner on the first screenshot are: Core Clock/ROP domain, 576 MHz; Core Clock/shader domain, 1350MHz; Memory Clock, 900MHz, Core Temperature, 70 degrees, Ambient Temperature, 62 degrees; Fan Speed, 1740RPM; Fan Duty Cycle, 60%.
I've run Defrag, CHKDSK/r, Ad-Aware, Norton, and Spybot multiple times. Same problem after re-launching FSX.
I doubt this is a video card issue, as I've had those in the past (both heat and driver-related), and they have always caused BSODs - not just FSX hanging.
Does anyone have any thoughts as to what might be causing the problem?