Bug#622346:

[Alex Deucher]

On Tue, Apr 19, 2011 at 6:22 AM, Boris Hollas <boris.hollas at gmx.de> wrote:
> Package: xserver-xorg-video-radeon
> Version: 1:6.13.1-2+squeeze1
> Severity: normal
>
> The problem is also present if the laptop lid is closed. If this is the
> intended behavior, I propose a change request: If the laptop lid is closed and
> an external monitor is connected, the external monitor shall be run at its
> native resolution.
>
> If this issue is not specific to the radeon driver, it should be filed for
> xorg.

This is not specific to the radeon driver.  It's up to the desktop
environment (gnome/kde/etc.) to decide what to do when the lid is
closed.

Alex