I run a wireless Print server which is detected on the network as a device with a MAC address (Media Access Control Address like a network card)
All that you have to do is set the computers up to print to a IP address (the static IP address of the print server) and it all works..
Printing over network computers never works well as the computer that the printer is connected to must be on as well as the printer to work..
For the price of 30-40 quid a print server is a must have for me personally

Canon actually now sell a range of wireless printers which produce fatastic quality prints