Found a couple of flaws in the MFC-5460CN software. When I first tried to use it tonight, it would scan a page, then pop up an error dialog requesting that I restart the computer. I know the USB layer was working, so where was the fault? After I restarted the computer, everything worked fine for a while. After a large number of 1-2 page scans, the software got confused. I had set one of the Custom Scan buttons to "200 dpi ADF". First, the custom label disappeared, and on my next attempt to use it, the Control Center application disappeared from the status bar. Starting it manually from /Library/Printers/Brother/Utilities/ControlCenter caused it to restore the custom settings I had made and everything worked fine from then on.