Airport Printing Problem With Canon Pixma 4200


Finally ditched windows for a mac (Powerbook G4 with mac OS 10.4) I have airport express and can go online wirelessly but having difficulties printing wirelessly when I connect my cannon PIXMA 4200 to the USB port on the airport (get no printer connected message). Works fine when directly connected to laptop.
Have played with airport utility settings with no success. Updated airport and printer drivers.
Can not find any info on cannon website. Cannon customer support not v helpful suggested needed a networked printer like PIXMA 4000R for wireless printing.
Can the Cannon PIXMA 4200 print wirelessly with airport ? And any idea what I'm doing wrong.
Any help would be appreciated.