Problematic Firefox Extensions. A handy wiki list of Firefox extensions which can cause trouble with the browser. Also includes workarounds, which is very handy. Strangely enough, there are some surprisingly mainstream culprits listed.
This article lists known extensions that cause unwanted side effects in Firefox or in other extensions and plugins, along with recommended workarounds. If you don’t see your problem listed, follow the steps outlined in the Standard diagnostic – Firefox article.