possible weird performance issue in macppc 7-beta

[Jeff Rizzo <riz%tastylime.net@localhost>]

I don't yet have enough data to characterize this fully, but several 
times over the last week, I've seen (or rather, I think I've seen) a 
performance issue on a powerbook g4 which I recently upgraded to 7-beta 
from 5.99.something.
Things seem to work OK at boot, and at some point after running for "a 
while" - hours to days - either performance goes out the window, or some 
sort of deadlock happens.  This generally manifests itself in a 
particular process or set of processes that just hangs out using most of 
the cpu.   Invariably, things look better after a reboot.
Anyone else seen this?  This is with a week or two old netbsd-7.