GTX 560 Ti - Twin Frozr II Problems

Hello Major Geeks!

I purchased a Twin Frozr II about a year ago. I could not get it to work, due to multiple problems and I figured I would try again now. I'm running into the same problems again, and I'm completely stumped on what could be happening.

I put the GPU in my case, like it's supposed to. I've done it before, I know it's correct. This case is particularly bad - it has strange clips to secure it rather than screws. You can screw it in, but it's in an extremely hard to reach angle and I don't know if it even works. Thats - I think - the cause of my problems. The GPU works fine. Sometimes, it will work for a day without any problems - I'm typing this with my GPU working. Then, randomly as far as I can tell, it will just stop showing the screen. The computer will still have power, but the screen no longer recieves any signals - it still has power, but no output from the computer. It's not a problem with any of the other compontents, as when I revert back to my old GTS 250, it works perfectly fine for ~6 months. I do not know why it is happening - I'm pretty sure it is not my power supply, as I upgraded it to 760 watts at the same time.

As I thought it may be a problem with support, I used the very high tech method of supporting it with a small piece of wood. This helped it a lot - it can now get up to 2 weeks without dying, but it still does it a lot. I honestly am clueless - my only guess is that it's the case that is not supporting it, as it works better with the support. However, you do not need to move the card after the crash, just boot the computer back up. Is it possible it is a malfunctioning GPU instead?