About that Yahoo post, yes, 1v is a big difference to components like CPUs but that 19/20v doesn't directly connect to anything. I also found a few
interesting replies (and the third answer on
this one) on Yahoo answers a while ago, don't believe everything you read! There is another DC-DC PSU inside the laptop that will change that voltage into 12v, 5v and so on then
another type of PSU on the motherboard will supply very accurate voltages for anything 'sensitive' like the CPU. It might just be a duff power supply. Expect to pay a bit for the official ones, as I said earlier a universal one might be a good idea.