No sound output - Lenovo R61e ThinkPad

[twr7cx]

I've got no sound output from the Lenovo R61e. It used to beep on start up because of a thermal sensing error (due to the Intel Extreme CPU I'm running in it), and the speakers used to work fine in Windows, but yesterday, it decided to stop making any noises!

I've uninstalled the sound drivers, no difference. I've tried headphones, no difference.

Any ideas?
EDIT: I ran ThinkVantage System Update and it seems to have solved the issue (as the sound is back)! Cheers anyhow.