Graphics card problem?

[GodLovesPunk]

Recently my 7950GX2 has been giving me some trouble. After reinstalling my computer (fresh drivers etc) my computer has been giving me problems. It will work just fine for about 15 mins but then after some time has passed my monitor (Dell 2405) will seem to lose signal and turn off, then regain signal and turn on... over and over until finally it just stays off (but the computer is still on). I did have the card overclocked slightly, but I haven't even been using the computer for a couple of months.. its just been sitting in my room. I recently moved into an apartment for college and I've been using my laptop. But anyway, is it safe to assume the graphics card is the problem? I'm just curious what others think, but I've already requested an RMA.