Hello,
I'm not very skilled with mechanics, but I've been lucky using my printer (HP All-in-one 4780) that I bought when I acquired my MacBook Pro in November, 2009. I've upgraded from Snow Leopard to Lion and now to Mountain Lion. What's happening now is that I can send one job to the printer and it will print, but I have to shut the printer off by pulling the plug out of the wall and then back on--in other words, rebooting--to get another job to print. So, I have to reboot every time I want to print a document. This is a real pain, because I'm generally not in the same room as the printer when I send a job.
Any help or advice out there? I'm not sure that this problem happened when I upgraded to Mountain Lion, but it was in that general vicinity.
Thanks for any help you can give!