??? The tool/utility “Webrep” is not working with Firefox v16. I have v16.0.2 for Firefox and Avast Free AV v7.0.1473.755. The toolbar “icon” is always “grayed out”. Webrep is enabled in the tools - addons (extensions) in Firefox. I did a check of Webrep with IE8. Webrep is working on IE8.
There are many such topics in the forums, this problem with FF 16.0.x has been acknowledged and will be resolved in due course (I don’t know when, I’m just an avast user).
Ok then … thanks. Hopefully this will be corrected soon. 
You’re welcome, hopefully so.