I got an issue of Ubuntu 13.10, the new created window does not always raise-up to the front. It is annoying, which makes me have to click the icons on unity launcher to focus on the new window. Furthermore, if I turn on a program which has already been opened, the system does not bring me to the program, only blinks its icon on the unity launcher. Again, I need to click the icon to get focus on the window. Seems the system does not smart enough to determine which window should be focused to. I'm pretty sure it did not happen in previous versions of Ubuntu. Any idea how to fix it?