This thread has been closed but the problem still exists
"This is definitely a problem. With multiple instances of the browser windows open. One in the background maximized and one in the foreground sized to access. I use a multi-monitor setup. and may also have a browser window open on the adjacent monitor.
When passing the mouse pointer over an area of the background window that is active, usually a JS list element, title bar, the full screen window in the background will grab focus and come to the foreground. This usually happens when the background window is on a website like Facebook or Twitter.
IMHO This is absolutely a problem of the background window having elements that are looking for a mouseover event while they should be anything but active in this way.
Windows 7 64bit."