Hi Shaun,
Interesting. I am using my HPZ3100PS & my HPZ3200PS printing from Mac OS X version 9.5, Mavericks. I upgrade my machines to this OS via a situation-issue not unlike yours.
Here's the interesting part that took me to X.9.5 from X.7.5. Last January, I was trying to print a rather large job on the HPZ3200PS, and it would print on paper 44" wide by about 72" long flawlessly from X.7.5, Lion, but when I went to print on canvas (nothing had changed but the media choice), it would fail at the last 6 inches. I burned through a very expensive roll of canvas on this project. I spent a week working with HP tech, and in the end when I told them I had experimented on printing the job from a computer with Mac OS Mavericks X.9.5 and it printed, they declared that to be the "answer," and so I had to upgrade the studio which I had previously standardized on X.7.5 prior. You say the newer OS is giving you issues and you are reverting to the older OS which is the opposite of my situation. Are we having fun yet? I wish I knew why these behaviors occur, but even getting kicked upstairs to a higher level of tech didn't provide an answer. I wish I had more to say that might help besides, I feel your pain.
Best of luck, and so long for now, Tom
