Crashes with 8.1

[tkalfaoglu]

After upgrading to 8.1, I had to struggle to get qmail back up, and now, (perhaps also due to the fact that I upgraded the system to Mysql 5.1), I have daily psa crashes.
1) Did anyone else find 8.1 to be unreliable?
2) Where can I find psa logs to diagnose the problem?

thanks!
-t