Can you give us details of the extensions that you are having problems with? Quite a few extensions that can display an icon in the status bar have a setting in its options/preferences dialog to display the icon. Check the extensions to see if this is the case with them. Are the extensions listed in the add-ons manager, and if they are do they have any error messages next to their name? Another thing you can try is the section on corrupt extension files at http://kb.mozillazine.org/Unable_to_install_themes_or_extensions Removing the files listed can solve some extension related problems.