Render starts then hangs/stalls indefinitely

Anytime I try to render now, C4D suddenly stalls shortly after the render begins. Doesn't seem to matter rendering Sequences, no multi-pass, QT movies, make preview, etc. I tried letting it run overnight and in the morning, no progress, just stays where it was. Quitting the render gives the spinning beach ball and forces me to force quit.

I'm on an 8 core Mac Pro with 8GB of RAM. Not sure how rendering architecture works, but I've tried everything I can think of. It's a 10 second logo animation, no multi-pass needed. There's a glow on a light that's animated, but even turning that off in renders didn't help.

Thanks for any help,
~C