I have ff on my laptop installed for a few months now. For a short while I also installed beta4-b8 and later on updated to b9. The addons where downloaded using ff 3.6.13 before I had the beta. I was a happy betatester untill b9 came on. The browser became slow and was hanging all the time I opened a new tab. So today I decided to uninstall the beta (used the uninstalling programs in the configscreen on windows7) I opened 3.6.13 again and instantly missed my add ons. I tried to de-activate them but it didn't work. I tried to de-install them but didn't work. Also tried to install them again (esp. the yoono add-on) but it gave an error installing. When I start ff it doesn't show my add-ons. It gives me the idea that ff doesn't see the add-on. It shows on the add-ons screen. As soon as I click on de-install or de-activate normally I get a button with restart ff now. That button doesn't show up either. When I click for de-install (or de-activate it doesn't make a difference) and close the add-on screen and open it again the restart ff button is there. No matter if I want to change any of my add-ons, de-install, de-activate or just leave it als it is. As soon as I restart ff everything stays the same. Add-ons still doesn't work and still showing up in my add-ons list and still can't de-install or de-activate them. I followed the steps by delete them from save modus and even deleted the map the add-ons are in. As soon as I start ff again they are still there and still can't de-install or de-activate.