Mobo or Video card issue ??? lost

Hello...

I have a problem with the display of my computer. I recently purchased an upgrade for my video card - went with a 4870 XFX 1 GB card.

Everything installed, it was great, games worked, stress tests, all good.

Fast forward to a few months later... Now when I turn the computer off and turn it on later the system boots up, the video card has power, everything is connected but nothing displays (like the video card is broke). Except if i turn it off and on a few times then it starts running like normal. It's very sporadic.

Once it's working, it will run forever. Never cuts out on me or stops working on restart. I can put it on sleep instead of shutting it off and it will start up again just fine.

So this only happens when i completely shut the system down. Is this a BIOS thing? Since it's only happening on a cold start. I'm very confused. Any help is appreciated.