So my beautiful new computer appears to have stability problems, and the only thing I can think of is that it's related to the RAM.

Issue:

Some amount of time after booting up the computer and using it, the entire system will lock up, leaving no option but to do a hard reboot. Near as I can tell, it tends to happen when the computer starts working a little harder. This could range from simply playing flash video (not even in full screen) to gaming at maximum resolution. I can do these things for 30 seconds to 5 minutes or longer, but eventually the system locks up. If I'm just doing light web browsing, it appears to last far longer, but I'm pretty sure it's locked up doing even that before too.

Troubleshooting:

The one thing I've been able to be 100% certain of is this: when I have all 6GB of RAM in the system, the problem happens, and if I take two of the three sticks out and leave only 2GB, it absolutely never happens. Never.

So at least I can get a stable system by taking out the RAM, but I do occasionally notice a performance hit compared to what I had before.

What could be happening? I ran memtest86 overnight, and it reported no problems after several passes. If it helps, I have this RAM, this mobo, this video card, and an intel Core i7 930 CPU.


*edit*
The one thing I know will always cause my system to lock up is flash video. All of a sudden everything is stuck and the audio is droning on and on with a split second of the audio from whatever I was watching.