After starting Firefox 3.5.11, opening mail.com, and clicking on the username field (to enter my username), I started receiving a pop-up titled "Werbung - Mozilla Firefox." My operating system is Windows XP. The problem described below does not appear in Windows Explorer. I believe Werbung is German for advertising, but I am not certain. One of the ads that appears in the popup window says "congratulations! You have won and ipad..." To close the popup, you have to go to a "daily contest winner" page. Using task manager closes firefox. Across the bottom of the screen, just above the "Start" button, I noticed "addclient.uimserve.net" I do not know if this is related. Does anyone know how to get rid of this nuisance?