Bet you feel rather silly now having splashed out on a new card just for UT2003 which is basically quake 3 with some of the free mods available for it. Actually thats a lie - Quake 3 with some mods can be fun.
UT2003 plays well on even lower end cards like GF2. There is nothing in the game which needs a major video card - only thing in it thats fairly revolutionary is the karma engine and that has bugger all to do with video processing.
But yeah your right about it being time to upgrade from your GF2, cant fault you for that. I just used this as a cheap excuse to have a go at UT2003 which ive not done for a while