Well, the problem could be my install techniques. We installed the rotors/pads very quickly (4 people, in like 1/2 hour) and it was dark, so I didn't get to install them as perfectly as I would want (i'm pretty anal about that). I think today I may reinstall my race pads again in preparation for my next track event in about 3 weeks.
Thanks for all the tips, I will definately clean the hub surface, clean the shims, re-grease the pins, etc.
just like on this DIY website (which IMO is very good and detailed):
http://www.motorvate.ca/mvp.php/301