Help with new Mac Pro display prob

Hey all,
I just purchased a mac pro 1,1 3ghz 8 GB ram 250HD that has little long lines pop up in the desktop and throughout the windows randomly. Does this mean the video card is going? I need to figure this out because the person i bought it from will give money back for not saying this problem and I need to fix it. I am going to use this computer for only logic 9. Thank you in advance!

One way to test the video card is to swap it out with another known good one and observe the results. You might also try another monitor to make sure it's not being caused by a defective display.