I have a quake3 bsp loader working but I need some serious help. I am trying to get collision detection working (w/ the bsp brushes) but its failing miserably. First I dont think I am loading the brushes correctly, second, if that gets resolved I think its a quick fix. Anyone attempted this? I am willing to share source if ur willing to help 
, its for a university proj.
have you read the quake3 bsp collision code in code dumb section of gametutorials.com
It may help you.