kernel panics
 

i have had this happen several times using pt 6.1/digi001/g4dual-1ghz/1.5gRAM/OS X.2.6, in the middle of a session, do something like choose a menu item (tonight it was changing the grid value)- and suddenly the curtain drops and the "you must reboot your computer" in four languages appears. in older systems i kind of expected ProTools to bring down the whole system, but in OS X that's pretty mean.
any reasons behind this sort of thing?
i've noticed also that when i have had PT crash that didn't cause kernel panic, it strangely bypassed the console and left no crash log....?