Mitsubishi WT-42413 Blue Green and Red Line

I have a Mitsubishi rear projection tv model WT-42413 that seems to have a convergence problem. The picture is great. The only problem is that at the top of the screen, you can see a red, blue, and green line going all the way from left to right. They are curved. I've also noticed that at the very top of the screen, it looks like there are some white lines that are straight and run across the screen from left to right. I don't mind those quite as much, but they are probably related. I've tried playing with the convergence a bunch, but it doesn't seem to help. The rest of the picture looks fine. It is just a singe red line, a single blue line, and a single green line. Is there any chance that it is dust or something?