Follow these steps...
Right after you install the game go to the C:\UT2003\SYSTEM\ directory and delete the UT2003.ini and USER.ini (i think thats what they are called) there are 2 patches, copy over the 15 day trial patch over to the specified directory, you can also copy over the MULTIplayer patch over but that disables the KARMA enginebut you can play online, so make a backup of the other one, when you wanna play online just copy it over and make a backup of the other one..... but for single player KARMA engine rocks, then when you run the game press tab and go to CONSOLE then type "preferences" and you can tweak the s&*% out of it, then your set..... it needs a hell of a system to get 60fps avg tho......g'luck
RaZoR