problem setting up extended desktop

[Joost Ringoot <joost.ringoot@oma.be>]

  Hello all,

Prequel: I have a Latitude D620 laptop. With Ubuntu.
I have successfully used  an extended desktop with different screens ( a 
HDMI Dell 19"  at office via docking, and a VGA 17" (noname) at home)

I had an issue not related to this with the graphics, for which I don't 
expect any feedback from this group, it is just  to illustrate the 
circumstances:
When I clicked  with the right mouse button on a node in XCDP 
(http://www.ecmwf.int/products/data/software/sms.html) The GUI session 
hanged, untill I went to console (CTRL+ALT+F1) and terminated XCDP or 
its parent shell.
This problem appeared to be generel for Ubuntu 10.04 local installs... 
Yes curiously enough, this was not an issue for remote X-sessions.
A colleague installed ubuntu 10.10 and told me the issue with XCDP was 
resolved after this upgrade.
So I performed the upgrade on my laptop and found also that the problem 
with XCDP was resolved.

Alas I am no longer able to use extended desktop, "mirrored  screens" 
setup does work however.
I was looking in the Ubuntu forums for help and left a message there a 
couple days ago, no answer yet.
Maybe any of you can help.
A clean solution would be nice but any help to get me more insight on 
why this happens or were to go with troubleshooting is welcome.


I first tried with the "Monitors" configuration tool of ubuntu, but this 
just fails without any error output.
I then tried arandr, this fails with this output:
XRandR failed:
XRandR returned error code 1: X Error of failed request:  BadMatch 
(invalid parameter attributes)
   Major opcode of failed request:  150 (RANDR)
   Minor opcode of failed request:  7 (RRSetScreenSize)
   Serial number of failed request:  32
   Current serial number in output stream:  33

On the website http://intellinuxgraphics.org I found some more info and 
tried the following without much success.

root@legolas:~# uname -a
Linux legolas 2.6.35-22-generic #33-Ubuntu SMP Sun Sep 19 20:34:50 UTC 
2010 i686 GNU/Linux
root@legolas:~# lshw | grep -i graphic
              product: Mobile 945GM/GMS, 943/940GML Express Integrated 
Graphics Controller
              product: Mobile 945GM/GMS/GME, 943/940GML Express 
Integrated Graphics Controller
root@legolas:~# xrandr -q
Screen 0: minimum 320 x 200, current 1440 x 900, maximum 4096 x 4096
VGA1 connected 1440x900+0+0 (normal left inverted right x axis y axis) 
408mm x 255mm
    1440x900       59.9 +   75.0*
    1280x1024      75.0     60.0
    1280x800       59.8
    1152x864       75.0
    1024x768       75.1     70.1     60.0
    832x624        74.6
    800x600        72.2     75.0     60.3     56.2
    640x480        72.8     75.0     66.7     60.0
    720x400        70.1
LVDS1 connected 1440x900+0+0 (normal left inverted right x axis y axis) 
303mm x 190mm
    1440x900       60.0*+   59.9
    1360x768       59.8     60.0
    1152x864       60.0
    1024x768       60.0
    800x600        60.3     56.2
    640x480        59.9
DVI1 disconnected (normal left inverted right x axis y axis)
TV1 disconnected (normal left inverted right x axis y axis)
root@legolas:~# xrandr --output VGA1 --left-of LVDS1
X Error of failed request:  BadMatch (invalid parameter attributes)
   Major opcode of failed request:  150 (RANDR)
   Minor opcode of failed request:  7 (RRSetScreenSize)
   Serial number of failed request:  32
   Current serial number in output stream:  33
root@legolas:~#

Thanks,


Joost Ringoot