Comment 33 for bug 217571

9.10, here's how i got my MFC-7820N to work again
1.) I uninstalled brscan2 (NOTE: apt-get remove complained about missing directories so i created them so it could finish uninstall)
2.) ran brsaneconfig2
 see http://welcome.solutions.brother.com/bsc/public_s/id/linux/en/instruction_scn1b.html
3.) launch xsane and now it found the device

I am a big fan of brother, there linux support has been great