This is a bad IC more than likely and it is a common problem of CRT Rear Projection television sets. The easiest way to tell is by doing as your friends suggest and that is to attempt to adjust the CONVERGENCE in the menu settings. This is an 11 year old television set and I can't really remember where in the menu you find that but I think it's under "PICTURE."
Here's a quick explanation of what convergence means and what you are doing when you adjust these settings: your television set's display is controlled by the three individual colored
projection "guns" with in red, blue and green, Convergence is exactly what it sounds like; converging the projection of the three guns perfectly so that they align perfectly on top of each other, basically synchronizing the three images so that they provide a perfect picture. Convergence can be off for a variety of reasons but the most common is caused from set being moved. You should always adjust your convergence settings after you move a set. Most convergence issues are minor where you notice a duplicate, shadow or "ghosting" of another color around the edge of the images on your display. Then there are at the extreme cases such as your where you get the extreme lack of convergence resulting in the "D" effect as you described.
Normally if it is just a convergence issue, even the most extreme cases with the 3D effect can be fixed by simply aligning the guns through the convergence controls on the user menu on the set but what you indicated about the bowing in indicates a much bigger problem. I'm assuming that it looks something like this:
Obviously not all sets are the same so your mileage may vary on exactly what it looks like but this the result of of the IC going bad and since your post indicates that you lack experience with TV repair, you'll have to have it done professionally and that's going to st you back at least $800. RP CRT's (and CRT's in general) are unfortunately archaic technology and repair shops don't sd a whole lot of work with it anymore. Also, again, this is an 11 year old RP CRT and this won't be the last thing to go bad on it.
Considering the age of the television and the cost to repair, it is far more cost effective to purchase a nice new HDTV. For the cost of fixing this set, you can get a Mitsubishi 60" DLP 1080p HDTV that's 3D ready even. Of course the price of LCD's and Plasmas have gone down dramatically as well so that may be an option for you as well. Do some internet searches. TigerDirect is good, NewEgg is as well and keep an eye out for online retailers who offer free shipping. Go to Reseller Ratings and sign up for their newsletter where they'll provide with links for the hottest deals of the day from all around the web and most often they include free shipping.
Good luck! I hope this answers your question.