Extensions seems still enabled but missing in extensions menu
After upgrading firefox to version 8, I was expecting the one time "Select your Add Ons" dialog to appear. This did not happen, instead I got a script error from one of my extensions "Zotero" and firefox failed to start.
I restarted firefox and it opened ok but Zotero appeared disabled (had a yellow exclaimation triangle icon over it). I went to Firefox->Add Ons->Extensions to see if it was disabled or incompatable but found that the window was empty with the message "You don't have any add ons of this type installed". now have several add ons which are still working (Firebug, Video Download Helper definitely still working) even though I cannot see them in the "Extensions" Menu and therefore have no way to disable/enable them.