Description of problem:
When I use the gnome-display-proporties tool to detect and activate my external 20.1" LG Electronics L204WT-BF monitor it reports that 

Requested virtual size doesn't match the available sizes: Requested=(2560, 1024), Minimum=(320, 200), Maximum=(1280, 1280)

The requested size was 1280x1024@75 which is entirely correct for the monitor and the suggested values by the tool.

Version-Release number of selected component (if applicable):
xorg-x11-drv-nouveau-0.0.12-7.20090302gite6c3b98.fc11.x86_64
kernel-2.6.29-0.159.rc6.git3.fc11.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Plug in monitor
2. Attempt to activate
  
Actual results:
above error message

Expected results:
secondary monitor activated

Additional info:
x86_64, da_DK.UTF-8