I use windows 7 on a Lenovo thinkpad, everything is up to date as far as I can tell. Sophos antivirus. Every couple of weeks, I get a large popup window that is titled "Software update" with the firefox logo beside it. The message says "It is strongly recommended that you apply this update for Firefox as soon as possible." The only other thing it says is a link "view more information about this update" and the options to click next, or cancel. No matter what I click, nothing happens, so I always just close the window. I wish I could attach the image b/c I took a screenshot of it. What the heck is this and how do I make it stop?