It crashes after "loading" the actual game area- that is, I load up my mission, go through briefing etc, and when I hit "Commit" again, it gives me an illegal op and crashes. It was doing the same thing before, except before it also provided that third error screen, and would crash after "OK." Cancel, of course, simply closed Freespace.
The test mission right now contains Alpha 1, a Margay and the A17t it's assigned to dock with, and various enemies delayed 60-sec plus (so I can watch the docking). The various enemies are all FS2 stock, so they shouldn't be presenting a problem.