Whenever I start Firefox browser since last two days, I have noticed a message Thank you for installing Screengrab appeared. It is already installed I did not installed recently. Today when "Thank you for installing Screengrab appeared" I clicked on Screengrab "fixed version". I thought may be I have to update something but I can see the same message appear again. (I wish I could add screen shot) Also, when more tabs are open I prefer Firefox warn me before closing but that setting were also changed and Firefox had closed without warning though I reset them via Options/Tab warn me when closing tabs". Weird things are happening after Firefox updated. Version 20.0 Note: I prefer computer security and got virus and security soft installed no problem found so far. Can someone help please. Thank you