Installing the Gutenprint and Gimp-Print for Mac OS X (10.2 and later) may help.
I have installed all drivers, etc.,
Updated drivers? What are the etc. if other than drivers?
FIGURED IT OUT.
In case anyone else is having a similar issue, the problem was that the first generation airport transmits on a 5Ghz band, but the Canon printer will only recognize a 2.4Ghz band (more common). The second gen airports are dual-band (5Ghz & 2.4Ghz simultaneously) and so I'm hoping getting one of those will solve the issue. If not, then I suppose the only solution would be to get a router that transmits on a strictly 2.4Ghz band.
Had same problem with Canon Pixma MP640. Printer is directly connected by Ethernet to Netgear wireless router to join the LAN. Laptops around the house (on wireless) stopped seeing the printer, it wouldn't appear in the "add printer" list and we couldn't print (no matter how many canon software reinstalls/updates and resets we did!). FIGURED IT OUT TOO. Its a CANON NETWORK IJ discovery problem. IT DOESN'T like 5 GHz band routers!!
I had recently changed router to a DUAL BAND Simultaneous 5/2.4 GHz Netgear. (previously Belkin 2.4 GHz). Also installed a Trendent Access point DIRECTLY connected by cable to router to extend wireless coverage. Access point is 2.4 GHz only.
So when laptops are near enough to the Netgear router, they join automatically (by preference) on the 5 GHz band. (you can see what access point/router and what band your device has joined on by holding down ALT key + click the wireless icon up in the menu bar. Get detailed info then). Laptop becomes 'blind' to the printer.
When move away to another part of house laptops tend to join on the 2.4 GHz band (because signal is stronger because 5 GHz suffers more attenuation and doesn't travel as far as 2.4 GHz) and hey presto!! can now print!
So its some subtle wirelss protocol thing with the Canon even though the canon isn't communicating directly via its own built-in wireless (use this if you wanted an 'ad-hoc' network instead of a proper LAN). The canon is directly wired to router and should use the router's wireless link thereafter but 'objects' to the 5 GHz wirelss link band.
i had the same problem ... i think u just need to install the right driver for ur Printer. try again.