Being in the software industry I can attest to the fact that power supplies aren't the only part of a computer that regularly fails to compy with specs. Most people would be shocked at the number of computer parts and peripherals that not only don't meet various specs but are utterly broken right from the start. USB devices that will crash a machine if it comes out of sleep mode, PCI cards that have timing issues, graphics cards that will crash the OS at the drop of a hat, plenty of devices that work fine on their own but won't cooperate with other peripherals and these are all shipped products that are on store shelves.