This may have been resolved elsewhere, but just in case readers havent found solution yet.
IF your JK crashes, due to the 3d Acceleration option, try this...
-Load JK, as soon as you get the option SETUP click that, uncheck 3d-Acceleration box.
-Change resolution to 640 x 480, click OK.
-Load a Multiplayer level ( like BGJ ) in this poor quality mode.
-Test your normal abilities in this mode ( run around, shoot your gun, saber on/off, etc)
-After 10 seconds of testing, press Escape, SETUP, check box FOR 3d-acceleration, change resolution to 640 x 480 ( same resolution as before ). Go back to game.
Many times, this resolves the problem
( this has to be done each time you close and reopen JK: uncheck, load, play-test, check, play )
For me, the problem was due to an update in NVidia video graphix card ( 6600GT ), which i believe they are still resolving, and making slow progress on.
Hope that helps some of you.