[Boris The Spider]

Looks temperature related to me. Open your case and use a can of compressed air. Be sure to clean any heatsink fins. Dust bunnys love to live there and keep your heatsinks nice and warm, just what you don't need.
Also, hold a finger on any fan blade before dusting fans. Letting them free spin in the path of compressed air can possibly damage them.

bohr-r, drivers for your card are now considered "legacy drivers" by ATI. Here is a link to that driver:
http://support.amd.com/us/gpudownload/w ... ng=English

Go down to just about the bottom of the page for the d/l link.

One thought, for not much money you could upgrade to a better card, not bleeding edge, but something a bit newer. Just saying.....