Hi martyjump,
Welcome to the HP forums!
I see from your first post that you have 2 Evy 4500's with the same issue printing 8x10 photos. I'm sorry to hear this, but I would love to help out as best I can :)
Let's start with testing the hardware. Could you please make a copy of an 8x10 photo and see if that is able to print completely?
Either way, I'd also recommend making sure you are Getting the Latest Firmware and Product Updates on the printer as well.
Let me know how this goes for you!