help with radeon x300 card

Hi. Here is the problem. I just got a pci-express card for free so since I have a free slot, I'm using it. My motherboard is Asus a8n-vm csm. I was using the integrated nvidia 6150 before. I uninstalled the nvidia drivers and then installed the latest catalyst driver. I can play games at a decent resolution now. The problem occurs when I try to watch anime and movies. For anime, I do not understand why it would sometimes go black and white pictures and then return to color every couple of minutes. For movies, it would give me a blue screen and then restart the computer. I was using K-lite codec pack's media player classic to play those videos. When I turned off the hardware acceleration, those problems disappear, but my videos become jumpy. If you could help, that would be great. Thank you ahead of time.