Shouldn't a 1500 VA UPS (new and charged overnight) be able to power a Dell Studio XPS with 2 internal disks? Nothing else plugged in. According to the APC web site, this should be enough for the computer and 2 monitors and 2 external disks, but it won't power just the computer for even 5 seconds - the conputer oscillates on and off as if it was getting some but not enough power.