I installed 3.0_STABLE on a PowerPC Mac mini a few weeks ago. I put the 
machine through its paces by rebuilding itself from src and 250-odd 
packages in a pkg_comp. So far, so good. But when I brought it into 
production, I started getting odd signal 11s from at least MySQL and 
Dovecot. (MySQL would also eat a table or two every day; nothing REPAIR 
TABLE couldn't fix, but yikes.)

After trying 3.0.1 and then a 3.99.23 kernel without improvement, I 
rolled back to 2.0.2 on a tip from another mini owner. With the 
exception of one failed pthread assertion, from which MySQL recovered by 
restarting itself with no visible damage, the mini has been rock solid.

I'm not in a position to experiment further on this machine, as I'm 
relying on it, but wanted to make sure I recorded this problem 
somewhere. I can send-pr as well, if that's desirable.

- Amitai