Comment 0 for bug 9237

When a window is unmaximized, the middle button at the top right of the window,
on the title bar, is an icon of the window maximized. When the window is
maximized, the middle button then becomes an icon of two smaller windows,
indicating that the window can be made smaller. However, on mouseover, the icon
becomes a maximized icon rather than staying an unmaximized icon -- the tooltip
remains the same.