Jeebus Rukkus, that card still giving you a hard time? I remember posting a bunch of shit in some thread from like a year ago, did you ever get to testing that stuff out?
The Ti-4200 is an old card now anyway, if you have some loot you will lose it when you see the quality/speed on a new card. I don't know what your budget is, but these are two badass cards:
9800XT
9800 Pro
Both very speedy cards. NVidia actually has some decent cards now, their FX line started off as a flop though so their rep is kind of fuzzy.