Weird DVD playback issue and internet video problem

Hello everybody and thanks for taking the time to read this. I'm not sure when it actually began but I do know that the problem was there on Monday when I tried to watch a video online and the flash video only showed up as a green screen that crashed the browser. A few minutes later I tried playing a DVD that had worked on the PC before and Windows Media Player recognizes that it's playing but only the sound plays none of the videos show up on the screen. It's the same thing in Media Center so I'm wondering if it could be a graphics card problem.

Several things I've done since:
1. Install a new DVD player in the system, same thing happened
2. Did a system restore to an update that occured Saturday, no joy
3. Undo the restore and reinstall graphics drivers, no luck
4. Install VLC Media Player, doesn't work right with taskbar but the DVD is playing fine

The only thing I recall doing that could possibly have ruined this was I removed the heatsink from the graphics card and applied my own thermal paste to the card in order to move a little more heat from the card, I know I did it corectly since all four screws are back in (games play just fine and temps seem a little high). Can anybody help me my last option is to completely reinstall Windows and I don't want to take the time to do that.

System Specs
OS: Windows 7 Home Pre 64-bit
CPU: Intel Core 2 Quad Q6700
RAM: 4GB DDR2
Mobo: Dell BTX P965
GPU: Asus Radeon 4870 1GB
PSU: Antec EA650W
HD: 320 GB Seagate