I have an E6520.  Everything was fine until the user spilled wine on it.  Had to replace the mobo and a few other parts.  Then I updated it to the latest BIOS A07.  Now when it is docked with the lid closed, and then powered on, it has no video on the dock monitor (dvi connected) until the login screen comes up.  The bios should show video almost as soon as it is turned on.  I would like to try an older BIOS version but cannot find older versions on the new dell support website.