I have several classrooms with fairly recent Intel-based Macintosh computers running 10.7. I have a server running Server version 10.5. I am trying to get a print server to work on these machines. Black-and-white printing has been made to work reliably, including with Quark and some other programs that are historically difficult. Color printing has proven not to be reliable. I can print from any workstation directly to the color printer, which is a Xerox Phaser 7750DN. I can print from the 10.5 server to the color printer. If I try to print from a workstation via the print server to the color printer, I variously get errors such as "Checking the status of the printer not permitted," or it will successfully start to spool the print job -- which takes forever and sometimes doesn't get past a certain point - roughly 80-90 % -- and then stops. If it does print, it comes up with a printout from the color printer that says "Stack error." When it's trying to send a job to the print server, it will sometimes flash a rapid message saying, "Printer does not support IPP-2.0/trying IPP1.1." All software on the machines is up to current upgrades.