demo crashes on mac dual 1gig

just installed invigorator pro demo,and everytime I try to import
a 3d object or try to use openGL AE 5.5 crashes(error 2 or just
freezes) I got 500 mb ram allocated to AE,and still got 250mb
left for my system,so that can't be the problem.
I'm really interested in the software,but need to know if I can
get it working on my system.
Can somebody help me ???