I noticed that the StartOJPEnhanced.bat file does not work with Vista 64-bit.
Because of this, I am providing a fix which is really simple to those who are decent with command lines, but is rather difficult for those who aren't this computer literate.
Firstly, open notepad as administrator.
Hit the open button and navigate to Program Files (x86)\LucasArts\Star Wars Jedi Knight Jedi Academy\GameData
Once there, open StartOJPEnhanced.bat. Replace the text with this (Provided by Nizwiz):
start jamp.exe +set fs_game ojpenhanced
BAM, the file will now work properly.