Life got rather busy for me, and I finally got around to pounding hard on the 0.21 beta this weekend. It's possible that it's only my imagination, or that since there was more to test, the games were lasting longer, but while I had been able to finish games at the end of Beta 1, I never came close in the latest version of the code. I was seeing CDTs after a few (several?) hundred turns and save files that wouldn't load. Are other people seeing this as well? Unfortunately, I didn't think of checking the SmartException details.
Other than that, I noticed times when I'd loose the "next turn" button until I'd click on a planet or do something else to gain the program's attention, and once, it just ran off into la-la land and never responded to anything.
I haven't seen anything in the forum to suggest that anyone else has seen this, which is the only reason that I'm the least bit concened. Then again, it could just be that I need to open up the case and blow the cat hair out of the CPU fan again.