I did a search but couldn't find anything exactly like what I was looking for, so here goes: I just got a new mac pro at work and am trying to set it up to work with our (PC) network printers. When I first opened up the Print Preferences, one of the printers (HP Color Laserjet 3600) appeared in the "default" list and works just fine. The others did not appear, so I found them in the "Windows" list and added them with the proper drivers. They are a Sharp AR-M620N and a HP Laserjet 5. Though I was able to add both without problem, when I try to print they both appear with "On Hold (Authentication required)" status, even though I've correctly entered my username and password. When I click "Resume" I get the window asking for the username and password again, but it never works. Any ideas?