Ubuntu 9.10, 10.04, 10.10, 11.4, 11.10, 12.04
1. Open "/lib/udev/rules.d/40-libsane.rules" file.
2. Add the following two lines to the end of the device list. (Before the line "# The following rule will disable ..."):
The lines to be added---------------------------
# Canon scanners
ATTRS{idVendor}=="04a9", ENV{libsane_matched}="yes"