Attached Link: http://www.geocities.com/lithunwrap

Just a note to second what Berserga said. I've used several conversion packages to take .cob to .obj, and they all seem to have trouble with objects made with lots of boolean operations.

The nicest package I've used is LithUnwrap, but it does not seem to be available as freeware anymore. It was at the link above, which will now lead you to a trialware prog.