I updated my Macbook to Snow Leopard OS X 10.6.3 this week (I know, I took my time with this), and ever since, Acrobat Pro 10.1.6 no longer recognizes my scanner, a Canon MG2120 multifunction printer. What can I do to make it work?
Try loading the latest driver available from Canon: http://www.usa.canon.com/cusa/consumer/products/printers_multifunction/photo_all_in_one_in kjet_printers/pixma_mg2120#DriversAndSoftware
There seems to be one dated 7/27/12. You may also want to completely reload the MP Navigator software.
-David