What do you mean you have an "Airport?" I am going to guess you mean you have an Airport Extreme and/or Airport Express. With the old printer connected (either directly to the computer or Airport Extreme/Express) run Software Update first to see the system is 100% up-to-date. Next check the cables and connections on the old printer. If you have switched USB cables and the problem persists disconnect the printer and turn the printer off. Next restart the computer in Safe Mode to clear some caches, it's possible one is corrupt. Then restart normally, connect the printer and turn it on. Next open System Preferences - Print & Scan/FAX (we have no idea what version of OS X is running on your computer????????????????) highlight the printer on the left, right click it and choose Restart printing system...
Also check Printer and scanner software for OS X Lion, Mac OS X v10.6 to see if the old printer is still supported and also use Printing Overview OS X Lion .
Finally PLEASE update your profile, in order to be able to help you at the very least we need to know the version of OS X you use (Tiger, Leopard, Snow Leopard, Lion) and what release. You can complete your profile by clicking Your Stuff in the upper right, then click Profile and complete the pertinent information.
