the right-click menu stopped working (it opens, but clicking on things doesn't execute the action)I guess you mean the context menu of the website? I didn't see this issue yet using FF 16.0.1 + FB 1.10.4 on Win7. Does it go away when you create a new Firefox profile and just install Firebug in it?
I posted to the Mozilla support forum and was advised to disable Firebug, and that multiple people had the same issue yesterday. Disabling firebug caused the error to stop.