Why do you have the CLJ 2600n hooked up to a host computer? Why not have it plugged in directly to the network itself?
As for the problem itself, I would guess it has something to do with the host computer itself. Compare the settings on the other computers to see if anything is different. Other than that I have nothing else right now.
I have a brand new HP Colour Laserjet 2600n which i am sharing over a Windows XP Star network. One of the usera, which has all the printing rights, the same as everyone else, cant print. The printing jobs appear in the jobs list, saying printing, but nothing comes out of the printer. If you cancel the print job and restart the printer spooler on the host machine the job then prints.