I purchased the MX320 after I checked and found that Canon have the drivers, which I downloaded and installed. The printer works fine, but the scanner is a no-go. YaST hardware lists two entries for the unit; lsb only one, the printer. Below are what appear to be relevant extracts from the YaST listing:
linux-hwp2:/home/john # sane-find-scanner -q
found USB scanner (vendor=0x04a9 [Canon], product=0x1736 [MX320 series]) at libusb:005:002
linux-hwp2:/home/john # scanimage -L
No scanners were identified. If you were expecting something different,check that the scanner is plugged in, turned on and detected by the sane-find-scanner tool (if appropriate). Please read the documentation which came with this software (README, FAQ, manpages).
As you can see, the scanner is identified, but in “standby” mode it is not identified. Canon provide User Guides for about 50 million Windows rubbish, but not for Linux. >:(
I shall pose the question to them and see if I get any feedback.