Im running Firefox 8 for Mac. The problem started when my google toolbar disappeared, after I intalled some add-ons. After I restarted google shortcuts 2.1.7.1 didn´t show anymore. I re- installed this extension, restarted again, and doesn´t shows. I restarted in Safe mode with add-ons disabled, cheking extensions, preferences, plug-ins... nothing. I restarted again in Safe mode checking the box: Disable add-ons, and now all my extensions are disabled no matter if I enabled them and restart, they become disabled again. The only ones that remain enabled are the plug-ins and the theme I had on, which is not the default 8.0.1 theme.