QTR-Quadtone RIP

A newbie to Quadtone here... I have an Espon 9600 Ultrachrome inks with an ethernet 
hookup thru Airport.  I loaded QT  and it asked for my IP address and I gave it the address. It 
printed fine and then I went back to my printer to print a regular color print and selected the 
regular printer in the list as I usually do. When I went to go back and do another B&W print, 
the computer could not find the Quadtone RIP. 
I think it is because I had assigned an IP address to it when I first loaded it and as the airport 
reassigns new addresses, the old address is no longer any good. I couldn't see any to 
reassign a new address to it without unloading the program and reloading it everytime.

My obvious problem is how do I now regain access to the QTRIP? Is there a way in the 
program to load it such that the address is open and accepts whatever the airport assigns it?

Will I have to actually go as far as having a seperate printer dedicated to printing only B&W?

Will changing how the printer is hooked to the computer  (erthernet, USB, Firewire) solve this 
problem?

Any and all help will be greatly appreciated!! Thanks!

PS: Please, don't assume because I seemed to use all of the words in the right place that I 
actually know what the H*** I'm doing!!