My Canon Pixma MP 610 is direct-connected to my iMac running OS 10.5.3 via USB and works great, but when I try to access that printer from my PB over Airport Extreme, I get error messages. I have used this same setup for over a year, but since installing OS 10.5.3, it doesn't work. I have the latest Airport Extreme firmware and the latest Canon driver in both the iMac and the PB. What is the problem? Any help will be greatly appreciated.