Canon MX310 scanner communication error with OS X 10.5.8

Does anyone have ideas to solve the Canon MX310 error message, "Cannot communicate with scanner." I'm running Canon MP Navigator EX 1.0. My MX310 prints & copies wirelessly using an Airport Extreme w/o difficulty. I have checked that the USB cable is connected, printer is ON and tried a shut down of both computer & printer then restart which didn't resolve the issue. The error id might be 155.0.0. I don't get any other error messages generated from OS X. Thanks!