There is an exception. The hack *MUST* be done for the 5400 board. However, the 5500 board will work *WITHOUT* the hack, but there might be issues with PCI. I'm not sure if this is true for the 6200 or 6300, but I was able to pop a 5500 board into a 6200 and use a USB PCI card. I haven't read if the 6x00 machines needed this hack, but it worked without it.

The hack is a must for the 5400 board, though.