Thanks for posting the link. I checked out the HTML source code responsible that showing up, and here it is in full:
<input id="gwProxy" type="hidden" ><!--Session data--><input id="jsProxy" type="hidden" >
It looks like this is being added into the WYSIWYG editor by the Skype Browser Highlighter in some users' Firefox browsers - more info here:
So this is not directly a Q2A issue, though it is worth fixing. I will look into this more and try to addess it in the next release. Perhaps CKEditor (which the Q2A WYSIWYG editor users) will release an update that works around it.