Well, I knew as soon as I posted, I’d have the problem again.
It seems to be when I’m playing the preview and dragging stuff around on the timeline at the same time. The preview window will freeze but the timeline will keep playing. If I press any other button than [save], the program will freeze up, and I’ll have to force close it. Waiting for the program to right itself doesn’t seem to work.
At least I can save it.
I can try uninstalling and reinstalling again. That seemed to help initially.