Thanks, Kevin, that's helped both on beach balls, and unexpected quits. At least I can save my work. Sometimes, a relaunch isn't enough and I have to power the Mac down.
Here's a problem I've had with 8.5 and not seen mentioned elsewhere: I'm getting a lot of underruns with the message: Exception: AFIFO_TAKE_UNDERRUN, CtrlBiFifo:Auto LFE 4.
The Avid usually refuses to play past that point in the timeline, and it's hard to tell exactly what gets it to go away. I have a suspicion that it has to do with audio dissolves, because they are usually nearby, but no firm evidence.
I'm also moving back and forth from 8.4.4 to 8.5, because of these errors, so maybe that has something to do with it as well.
Looking forward to the point release to fix these stability errors, because in general the update is very good.