I've actually encountered this on a Gateway at a previous job. The problem occurred whenever anything was sent to the printer (weird, I know). After replacing the speakers, printer, and motherboard with no luck we sent the damn thing in (and it came back with a new PSU).
Also, at first I thought this topic would be about
this. Which is really, really cool in my opinion. I think I read an article on slashdot about a year back touting its success in a server room environment.