We do have a similar problem but when I'm playing, it doesn't occur.
A few days ago I turned on my computer to meet that wonderful "No signal detected" message. I tried a few things before I plugged my video cable into my mobo, all of which didn't work. So I used my onboard video and looked in my device manager to see that it simply wasn't seeing my graphics card as being there at all. Later in the day I turned it on to find that my onboard video wasn't working anymore and for some reason my graphics card started working again (it's on auto-detect so it'll only have one or the other running at once). It worked again for a few hours, until I turned the computer off.
After a day of looking about stuff online, I saw something about disabling the onboard graphics in the bios. I looked around and found no option to disable either of the video cards, but found an option to change it from auto-detected to detected both onboard video as well as my card, meant for multiple monitors. That worked all of yesterday. This morning it was working fine until while running my computer it randomly started changing resolutions, like my card was turning on and off. I reset my computer to find the video card doesn't work yet again.
It's looking like it might be the pci-e v1 compatibility issue some were talking about, but changing that setting to read both video cards might help somebody's problem.Sleeker Mouse with the New Gigabyte M8000Xtreme Mouse