This one is pretty straightforward.  Whenever I switch Rapture Pro to Multitimbral mode Sonar instantly freezes and crashes.  Don't think that's supposed to happen.

I do not use the multitimbral mode. I have tested it on my machine some time ago to answer a question about it here. It did not crash at that time. Just tried again with a new project toggling multitimbral mode does not affect SONAR at all. Are you still trying to run RPRo with ASIO set to 64 buffers?

It seems to only be happening on an old project I was working with this morning. so I guess it's just a weird bug in that particular file.  I tested it out on a different project and didn't have the same problem.  /shrug
 
As far as the buffer, RPro is unusable for me at anything beneath 192.  The audio glitches are just too bad and I'm afraid I'll blow a tweeter.  I've also found several patches with missing multisamples, so I'm suspicious that there is something else going on here.

I'm using MOTU's ASIO driver if that makes a difference.