Also worth mentioning that I have twice found very recently that some very weird problems, one with a one-gig AMD Athlon and one with a PIII-750 were resolved by installing a new CMOS battery. I'm getting the distinct impression that these batteries are just not lasting as long as they used to. I can recall when CMOS batteries lasted four or more years. These carked it after about two. Maybe the battery-makers have reduced the capacity with the intent of selling more batteries (but instead just cause more motherboards to be trashed/replaced). Or maybe the motherboard-makers are getting smart and only installing inferior capacity batteries.
However, having bad-mouthed the M'board makers, only today my aged father was saying that his hearing aid batteries (also silver zinc) are lasting about half as long as they used to. As I usually get them for him, I can verify that. So is it all a plot? Planned obsolescence is a fact of modern life.