Any time I open a new window, whether launching FF or opening one during session, all the content of the web page and the menu bars are located as though the window was bigger than it actually is. That is, that should normally be on the right side of the window is missing, and web page content that should be centered in the window is pushed to the right. All I have to do is resize the window and everything snaps to it's proper position. It looks like it's rendering the page and menus as though the window was the full size of the screen (just a guess).