If it was on XP I'd say go in device manager and look for an IRQ conflict between the video card and the interface(s) especially as they are all pci. But on windows 7 you can't manually assign IRQ's. Still that's exactly what that seems like, although I'm afraid on windows 7 it would not report it as a conflict even if it allocated an IRQ address being shared.
I guess to troubleshoot it you could disable the nvidia and see if it happens using the stock windows video driver. You 'll be limited to 1028x768 or some other archaic resolution though.
My laptop has an nvidia and I remember it taking a couple driver updates to eradicate some similar behavior.
Maybe check out xperf/Windows Performance Toolkit. I've seen many people use it a situation like this. They run the WPT and trigger the wonky behavior purposefully and hopefully the process monitoring and graphs will allow you to pinpoint what process or conflict of processes is spiking the system at the moment you get the glitch.
http://msdn.microsoft.com/en-us/perform ... 25801.aspxNo real answers, sorry, but I hope maybe something here gets you on the track of the culprit.
I love the bug where it starts to trace wherever a window is dragged, and makes all kinds of trippy patterns. but I'm a Mac guy so no idea if that sort of stuff is common)
