I`ve got EXACTLY the same problem: I suspected my BIOS primarily, but that is only because I`ve got another problem: I hope it would be symptomatic and would help to solve this problem: a month ago, my computer couldn`t start, so, I took it to the service. They found that my motherboard is malfuncioned, so they replaced it. However, some problems occured again immedeatly after it: after screen saver, picture went off, and I have to restart computer. Once, I couldn`t even start it again, but, luckily, it was only once. Last night, I couldn`t start a DVD, and I dound that there is no DVD drive at all- actually there is FLOPPY INSTEAD, and I have no floppy at all...
Is it Vista or BIOS? Anybody knows?