I got it modded not to long ago and I noticed a lot of ghosting in all the movies which are recoded in divix video. The guy that did the work said, that's typical in the videos, but I noticed it when I was playing the amazingly slow Castlevania for Super Nintendo on it. And I really noticed it when playing Ninja Gaiden (original XBox game) I don't anything about modding or what is even in an Xbox. Can someone tell me if I've been had? I have this bad feeling he stole the original ggraphics card and replaced it with a piece of crap. BTW, I did a new TV which is an LCD TV with a rewriting time of 8ms, somehow, I don't think that's the problem but I'm really unsure.
well, with DivX it will have a little bit of a quality issue compared to a DVD. But this should in no wau effect the graphics on a game. Have you tried messing around with the AV cable in the back. I know mine is a little wacky and if you do not have it in just the right position i will get a very bad, or even no picture. Sometime mine even did it when i started up and i have to unplug the AV cable from the back of the Xbox and then plug it back in, then it will clear up the picture.
Also for a quality upgrade, if your TV has inputs, you need to go out and buy a set of Xbox component cables, they are much better then the stock composite cables.
I am not even sure if it is possible to remove the graphics from an Xbox. It is most likely not a card like a PC would be, but an actual chip soldered to the motherboard.
You may also want to find out which chip was installed if you do not already know.