Well, I found one strange duplicatable bug when in Ultrabeat...
I found that tweaking an UB drum sound (any parameter) when Logic is "not" playing and then hitting "play" causes Logic 9 to crash.
No "Save As xxxx.(crashed)" message, just the error log/send to Apple dialog pops up.
This happened to me a few times today since upgrading the OS.
This might be an isolated bug in my system OR is a Logic 9.0 / OSX.6.1 issue.
I'd love to hear if anyone can duplicate this... Just remember to SAVE before tweaking sounds in Ultrabeat!!