Toshiba TheaterView color bending?

Hi, I'm new to this forum, but hopefully one of you can help me out.

During the past few months I've been having some issues with my Toshiba TheaterView... I've owned it a while, and recently I've started to notice that the red images are separating and shifting inward. When a color image is projected across the entire television, there is a clear bending pattern in which the gap becomes greater the closer the image is to the center of the TV. The curious thing is that the degree to which this happens seems to be random. At some times, the gap is minimal, while at others, it can be from 3 to 4 inches from the norm, which makes the viewing experience rather painful if I do say so myself. Oh yeah, and the gap we're talking about is a vertical gap; it's in the lines that run across the screen. I've tried to adjust the color convergence using the appropriate RV knob, but the center line is almost dead on so any adjustment would just throw another section of the TV off. Recently the RV knob has stopped responding, too, so that complicates things a bit more.

I don't know a whole lot about electronics, especially the inner workings of a television, so this has put me in a bit of a quandary. I'm thinking there might be a problem with the red "TV tube" that causes the red wavelengths to bend inward, but I'm not sure. For the record, the BH and BV lines align themselves perfectly, and the RH is almost always perfect as well (although on some bad nights it's very slightly off). I'm really not sure where to go from here, so if anyone has advice on what steps to take to alleviate this problem, I would really appreciate it.

If you need model information, let me know.

Thanks in advance,
Tom