sudden shutdown

[d-track]

system shuts down in a funny way.

it happens occasionally, seems like random. like once in some weeks.

it doesnt turn off the machine completely, the system fan is spinning the monitor usually blinking and glitching in patterns, sometimes shutting down. my usb soundcard also shutting down and as i can hear the HDDs also down.

only restart helps then.

 

asus p5gcmx1333, c2d 2.66, 2gb ram, onboard intel gma950, SL 10.6.4

 

any idea?

thanks

 

ps: i have multoboot and never experienced this on windows xp