Oh, I was getting so frustrated that I couldn't use my new Canon Pixma MP620 printer with wireless on my Mac! I gave it a static IP address, and went through IP Printing. Crash! from CIJAutoSetupTool, and Console said 12/24/08 10:25:29 PM com.apple.launchd ([0x0-0x1e01e].jp.co.canon.ij.print.cijautosetuptool) Exited with exit code: 255 . Grr! I read this thread, and discovered the answer is to use
System Preferences>Print & Fax>+>More Printers>Canon IJ Network
So when I had IP selected, I was already on the wrong path, because I needed to select More Printers instead. D'oh!