Last week I uninstalled Sophos and switched to Avast. A couple problems:
1: the auto-updaters in Firefox (DevEd) and Steam now complain about invalid security certificates
2: in Avast > Preferences, both Shields tab and Updates tab, all of the checkboxes are grayed out and unclickable. I cannot disable or modify any of the shields, nor can I modify or manually run any updates.