OK, last week my old faithful PB G4 15" decided to do an instant, unprompted shutdown and reset my system clock to December 31, 1969. Everything came back after one niggling Safari issue and worked fine. Last night, it did the same thing to me again, this time I managed to avoid the Safari issue among other niggling things that happened due to the clock (hint: don't open any applications until you reset the clock). My big question is: Can a failing PRAM/clock battery cause random shutdowns? or am I witnessing the slow end of my trusty G4 PowerBook? It looks like a PRAM/Clock battery will run about $30, is it worth it to even try for my nearly 5 year old laptop? Or should I start looking to an upgrade? I did zap the PRAM this morning and I've done some test shutdowns without the clock being reset, so it might not be the PRAM/clock battery at all, and it may not even happen again, but I thought I'd see if anyone had any suggestions so that I don't end up with a completely dead laptop in the near future without any planning for the replacement.