Please feel free to move this to main Firefox section if necessary. For the last two months for no good reason I can add toolbar buttons such as Bookmarks and history,FEBE backup, etc which promptly disappear on closing / reopening Firefox, although the " bookmark this page" option, fails to work at all. Have tried Firefox 2 and 1. x versions including uninstall/reinstall with no success. Many checks have suggested that the system does not seem to have any trojans, virus' etc. Has any one a suggestion?