hmm odd... try restarting your comptuer and then doing it.
i just hope this works for you b\c it worked for me.
A great mod for Jedi academy
www.moviebattles.com
Computer Rig-
64-bit vista
23.5 inch LCD + a 19 inch
Q6600 intell qaud
4 gigs of ddr2 ram
8800GTS 512 video card @700mhz