If you disconnect your Canon CanonScan LiDE 80, 50, or 30 scanner, be prepared for thousands of logfile entries while the scanner driver searches the USB bus for the scanner.
Looking for devices matching vendor ID=1193 and product ID=8717
Looking for devices matching vendor ID=1193 and product ID=8718
Wonderful. Since I permanently deinstalled the scanner to replace it with an EPSON Perfection 2400, I ended up running the driver delete utility to nuke it from my system.
No more errors. Joy.