Check this thread by another member that appears on this Board (Printing Board) as there are many people that are experiencing the same problem.
There is some information on the net saying that there is a major problem with 10.6.8 and network printers (all). The only remedy for the moment seems to be to reinstall 10.6 and use the combined updater to 10.6.6.
My 8560DN shows it is paused. I can click resume printer and it immediately goes back to paused. The screen on the printer says it's ready for printing. I've tried restarting the computer and shutting off and turning back on the printer. I'm using a Mac with OS 10.6.8 and print drivers are current.