User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:14.0) Gecko/20100101 Firefox/14.0.1 Build ID: 20120713134347 Steps to reproduce: Open my mail, which gave me a couple of forum-notification messages. I normally click these, and hit delete to remove the mail, and to get the next one, opening all the relevant forum links in Firefox before going to Firefox and actually reading the posts. Actual results: Firefox stole the focus from my mail application. As such I'm required to reactivate mail, then hit delete, then click the next link, and then do it all over again. Windows shifts it's focus to Firefox on each click of an HTTP link in an external program. Expected results: Firefox should have left the focus with the external program. There is a known fix for this: http://labnol.blogspot.nl/2006/07/secret-firefox-trick-prevent-browser.html Sure enough, browser.tabs.loadDivertedInBackground is still set to true, and yet Firefox steals the focus. Now that might have been changed, so changed it back to it's default of false, and restarted Firefox. No change in behavior. It still takes the focus from the other program. Changed it back to true, restarted again, and again it steals the focus.