Strange 'buntu crash

[edwardp-mh2Nk+tgbQM at public.gmane.org]

10.04 LTS - 32-bit system just crashed, displaying the Xubuntu splash 
screen, frozen mouse pointer and both the Caps Lock and Scroll Lock 
lights on the keyboard flashed on and off.

Rebooted system, it did not go through a file system check (I thought it 
would) and it came up fine.

Any thoughts as to what might have happened?