I recently got around to installing the Mavericks upgrade, on my iMac 21" 2012. Everything seemed to go OK with no obvious problems, and I prefer the new look of some apps such as Calendar and Contacts. However I have been trying to print today, and the Canon MG8200 just does not respond except occasionally after I have turned it on and off a time or two. It is using WiFi, and was often a bit slow to wake up with Mountain Lion but always got there in the end. I have tried restarting the iMac - no change. Any suggestions please?