I did let it run all night and it locked up again under OS X 10.1.4. This time I had a shell window in the foreground with the kill command for the pid of LimeWire already entered, just not pressed return. Everything appeared to be frozen (gui wise), but the shell windows still worked. I did press return and the CPU load meter immediatly returned to normal levels, but the LimeWire window did not disappear from the screen and the gui was still frozen. Typing "ps ax" on the command line did not run to completion either. I just had to reset the machine.