There is a solution (I'm running Snow Leopard on a Core2Duo iMac, but this problem arose when I was running Leopard on a G4 PowerBook too).
Problem:
You download the OS X driver for the scanner from Canon's site. I already had the CanoScan Toolbox (4.1) stored on an external drive.
You unzip the driver and run the VISE installer. After a search it finds your copy of Photoshop (and maybe even the CanoScan Toolbox), and you click to install on that/those location(s).
You get a couple of error messages, which you click through.
You restart your computer and launch Photoshop. The Import menu shows the Scanner so you select it, and immediately get an error that the driver is wrong and the process will abort.
Solution:
BEFORE you restart and run Photoshop, and with the installer still open -
1. Copy the Into_CFMSupport_Login & Into_CMPrefs folders to
- Applications : Canon Utilities
- Applications : Canoscan Toolbox
and remove the prefix Into_ from each folder
2. Check whether the installer placed N067U_Library.shlb into the top level (not User level)
Library : CFMSupport
and if it didn't, move it there yourself
THEN restart, and launch Photoshop. It worked for me, but whether it will work for everyone, I don't know.