I have been having trouble with my Canon mf4350d. It used to work with no problems prior to upgrade to Windows 8 then 8.1. Printing and faxing work fine, but when I try to scan, the Toolbox program hangs, dims out on the screen and says Not Responding. It's as if the Toolbox program does not work in Windows 8.x. When I remove and reload the drivers and Toolbox software, it works again for the first time but then will not work the second time. Any ideas on how I can fix this? I need a scanner that works all the time.