This new update to Avast! add-on for Firefox disables Disqus in Firefox. Please fix it. I have to disable it for Disqus to work.
The AOS browser extension is causing various problems for some users, disabling is the best bet at the moment although I am certain it will improve as Avast! work on tweaking it. 
Same issue with Pinterest and the addon. Tried setting up exceptions in Avast, but got no where with that.
The addon says it was last updated Nov. 26, 2013, but the actual problem just started yesterday. There is also a topic with the same problem with the addon in Chrome, so it’s not just a bug in the Firefox addon. the last Avast update was yesterday, which is when the problem started for me. It seems it’s an issue with the latest Avast! update, rather than a flaw with in the browser addons.