[SOLVED] Xrandr does not detect second monitor-Dua head problem

[IronArjen]

I have two identical Monitors and thanks to the new X setup with Xrandr 1.2 I had no problem with the first monitor. Then I plugged in the second (PC off) switched on the PC and yes: both got signal. But the same. Reading the page of xrandr regarding setting up dual head besides an Unbuntu howto I understand I need to know how my monitor are addressed. This doesn't appear to work since xrandr only shows 1 monitor. What is wrong? Below terminal output followed by my xorg.conf

arjen@Comparative_Genomics:~$ xrandr -q
Screen 0: minimum 320 x 200, current 1440 x 900, maximum 1440 x 1024
default connected 1440x900+0+0 0mm x 0mm
1440x900 75.0* 60.0
1280x1024 75.0 70.0 60.0 47.0 43.0
1280x960 60.0
1280x768 76.0 60.0
1280x720 60.0 50.0
1152x864 75.0 70.0 60.0 47.0 43.0
1024x768 75.0 72.0 70.0 60.0 43.0
800x600 75.0 72.0 70.0 60.0 56.0 47.0
720x576 50.0
720x480 60.0
640x480 75.0 72.0 60.0
640x432 60.0
640x400 75.0 60.0
512x384 75.0 60.0
400x300 75.0 60.0
320x240 75.0 60.0
320x200 75.0 60.0

# xorg.conf (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg

Section "ServerLayout"
Identifier "Default Layout"
Screen "Default Screen" 0 0
EndSection

Section "Files"
EndSection

Section "Module"
Load "glx"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "es"
EndSection

Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
EndSection

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Device"
Identifier "Configured Video Device"
Driver "fglrx"
Option "EnableMonitor" "auto"
EndSection

Section "Screen"
Identifier "Default Screen"
Device "Configured Video Device"
Monitor "Configured Monitor"
DefaultDepth 24
EndSection

[IronArjen]

Although i have not yet figured out the ins and outs of xrandr and dual head or Big desktop, at least I solved this for my machine. It turned out that the propietary driver (ATI fglrx) blocks this output, whihc doe not mean you cannot set up dual head. Using the intel from

aticonfig --help

I managed to get dual head working but with screen 1 (=my second screen) in incorrect resolution. Trying to correct this aticonfig tells me screen1 does not exist. If I type

aticonfig --resolution=0,1440x900

the resolution of the second screen does get corrected. There is something wrong here with the ID of my second screen. Bigdesktop, even with appropriate options set always ends up in clone!