Umm, if I ever said it's probably video card memory, scratch that.
Video card memory going bad usually gives you BLACK squares (usually) around the screen, and they're most often flat and perpendicular to the screen (i.e. they're not on objects of the game necessarily). Alternatively, sometimes the textures start mixing up with other textures or turn into psychedelic colors (or just one of the textures would fuck up), but once they're fucked, they do NOT flicker. They stay fucked up. The latter might be due to the core / temperature too though. Sometimes (either core or ram), there's black lines around objects (like every frame black random lines) but usually they end up in a complete crash less than 10 seconds later...
Also, I don't think you can usually capture the memory glitches with fraps, which leads me to believe it might be driver issues.
Seeing this, I actually feel like it's either a driver glitch or your video card core is overheating (or "going bad"). Try updating drivers/switching drivers. For monitoring temps something like MSI Afterburner or even GPU-Z should be able to do it.
Monitor some temps during the game.
Also, you might want to see if your video card crashes or displays glitches with Ozone3D's "Furmark" - look it up. Run it for 10-15 minutes. Beware - running furmark rapes your video card probably like it's never been raped before, so it might crash in furmark, but you might be able to play games fine (that would explain the glitch though). A properly cooled, stable card should never ever crash on furmark, or even glitch.
