6 months after the last post here, I still have exactly the same problem with FF only on one laptop. I use KIS in 9 systems. I have done all that has been suggested in this post. I have switched to Chrome to manage with this issue. One clue might relevant. I have installed the KIS addon to FF but KIS still persists with the recommendation that I install KIS add in FF. There is some communication missing between FF and KIS.