radeon + laptop/external monitor (through docking station) problem

[kewlemer]

Hi all,

My set up is basically a laptop connected to an external monitor
through a docking station (Fedora 9 + AMD64).

Laptop has a Radeon Mobility 7500 card (screen resolution 1280x800)
and the external monitor is Samsung SyncMaster 225BW with 1680x1050
resolution.

The problem is that when I keep the laptop docked and access it
through the external monitor, I get a display like this -
http://picasaweb.google.com/kewlemer/XorgRadeonLaptopDockingStationExtMonitorProblem/photo#5212182196419140690

It looks like X incorrectly senses that both my laptop and monitor are
plugged. Once logged in I can get rid of the smaller 1280x800 laptop
screen boundary by doing a  -
xrandr --output LVDS --off

Note that if I log in using KDE, it automatically adjusts to
1680x1050. GNOME however keeps what the login screen displays and I
have to execute the above xrandr command to get rid of the smaller
1280x800 boundary.

Can some please tell me how to ensure that X starts with the right
resolution when I boot from the docking station ? Once X throws the
right screen size, GNOME would automatically use this and I wouldn't
have to do the LVDS --off each time I log in. I have googled around
and tried tweaking xorg.conf in different ways but no matter what I
try it still displays the additional laptop screen laptop screen at
bootup.

Here is my current xorg.conf -
http://docs.google.com/Doc?id=ddjtzn4_2pns85s

Here is the output of xrandr -q -
http://docs.google.com/Doc?id=ddjtzn4_8ttxtm6ck

Here is the output of xdpyinfo -
http://docs.google.com/Doc?id=ddjtzn4_9ks5bsqcp

Here is the content of Xorg.0.log-
http://docs.google.com/Doc?id=ddjtzn4_1fj2tqp

Any pointers/suggestions are greatly welcome.

Thanks,
KM