I need to select printer software but can't find any link to the software just installed on my computer & system preferences can't find it automatically. Appreciate your help.
From the Default Add printer view, with the MF4350d selected, change the Use menu to "Select printer software" and in the next window, you can search through the list of installed printer drivers or type MF4 in the Filter field. This will short-list the amount of drivers displayed and show "Canon MF4320-4350 UFRII LT", which you can select then press OK and then Add to complete the printer queue creation.
No problems with having Gatekeeper enabled. The UFR2 v2.41 driver is digitally signed so it will install without any workarounds.
You can check if the driver did install by opening Finder and navigating to Mac HD > Library > Printers > Canon. You will see a UFR2 folder if the driver installer did its job.
If the UFR2 folder is present, try a restart of the Mac and then try to add the printer again. Hopefully this makes the UFR2 printer models appear for you.
Got two-sided printing to work: when printing, even though it's grayed out under "Layout," under "Finishing" it gives you the option of switching between 1- and 2-sided.
Got the driver to install and work as well, however double sided printing doesn't seem to work anymore (it worked fine in Windows). Does the Mac driver not support two-sided printing? Mac OS X Mountain Lion here as well.