I had a TI-4600 back in the day...bought it for nwn...and yeah 2 years ago... it finally busted out. However for a couple years before I got a new machine...I would get strange graphics like that... a green strip , rainbow strip and so on. Its a sign of heat, and possible damage. Sooner or later the video card will give out. Watch the frequency,,, if you are finding its happening all the time, I would suggest looking for a new video card.