When I print over a LAN using my Mac Pro, the print process always gets paused. This only happens when printing from the Mac. Could the problem be the driver used by the Mac for the printer? The printer is an HP 952C. 
David Williams

We don’t think the driver is at fault, however, the printing protocol probably is. Go to System Preferences > Print and Fax. Try removing the printer, then re-adding it. Change the IP printing protocol from whatever default is currently used (probably Internet Protocol Printing or IPP) to HP Jetdirect – Socket. In most cases that should fix the issue.