Screens and Graphics Preferences fails to detect updated monitor.

Thank you for taking the time to report this bug and helping to make Ubuntu better. This bug did not have a package associated with it, which is important for ensuring that it gets looked at by the proper developers. You can learn more about finding the right package at https://wiki.ubuntu.com/Bugs/FindRightPackage. I have classified this bug as a bug in displayconfig-gtk.

Seems like the new revision uses a different edid. Please append the output of the following commands: "sudo get-edid|parse-edid" and "sudo ddcprobe".

I tried the get-edid and parse-edid, but those commands were not found on my system.

Here is the output from ddcprobe:

vbe: VESA 3.0 detected.
oem: NVIDIA
vendor: NVIDIA Corporation
product: G71 Board - p455h7s Chip Rev
memory: 262144kb
mode: 640x400x256
mode: 640x480x256
mode: 800x600x16
mode: 800x600x256
mode: 1024x768x16
mode: 1024x768x256
mode: 1280x1024x16
mode: 1280x1024x256
mode: 320x200x64k
mode: 320x200x16m
mode: 640x480x64k
mode: 640x480x16m
mode: 800x600x64k
mode: 800x600x16m
mode: 1024x768x64k
mode: 1024x768x16m
mode: 1280x1024x64k
mode: 1280x1024x16m
edid:
edid: 1 3
id: a026
eisa: DELa026
serial: 324c4853
manufacture: 38 2007
input: analog signal.
screensize: 52 33
gamma: 2.200000
dpms: RGB, active off, suspend, standby
timing: 720x400@70 Hz (VGA 640x400, IBM)
timing: 640x480@60 Hz (VGA)
timing: 640x480@75 Hz (VESA)
timing: 800x600@60 Hz (VESA)
timing: 800x600@72 Hz (VESA)
timing: 800x600@75 Hz (VESA)
timing: 1024x768@87 Hz Interlaced (8514A)
timing: 1024x768@75 Hz (VESA)
ctiming: 1280x1024@60
ctiming: 1600x1200@60
ctiming: 1152x864@75
ctiming: 1680x1680@60
dtiming: 1920x1200@59
monitorserial: GM50479L2LHS
monitorname: DELL2407WFPH
monitorrange: 30-83, 56-76

Maybe I did something wrong but I had the same problem when switching my two NEC MultiSync LCD 1850X to two Acer AL1916W.

1. First I shutdowned my computer and made the switch
2. Then I booted and noticed weird resolution glitches and desktop effect didn't work (restricted driver got disabled ?!)
3. I peeked in xorg.conf and found out that the NEC configs were still there
4. I tried to manually change the specs, now the secondary screen didn't work
5. I tried to reconfigure with displayconfig-gtk and restarted X
6. Seemed to work but I had to edit manually xorg.conf to remove virtual mode, which was to big for my screens
7. I enabled restricted drivers and rebooted
8. secondary screen was flashing colors in a psychedelic way
9. reconfigured all over again and managed to get things working
10. Tried to enable desktop effect without success, I get the message "The Composite extension is not available"

It took me about 1 hour to change my monitor and it was a real pain in the ass and I still haven't managed to get back desktop effects ..

From a end user POV, there is definitely some usability work to do here. It's painful to say, but it's nothing comparable to Windows and Mac OSX experience.

Thank you for reporting this bug and for your efforts to make
Ubuntu better. As Xorg has improved this past year, an unfortunate side
effect of these improvements is that it has rendered several design
assumptions in displayconfig-gtk obsolete. So, starting with Hardy we
are no longer putting displayconfig-gtk forth as a primary configuration
tool, and are putting our development focus into the Screen Resolution
applet. As a result, we do not plan to fix this bug and thus are closing
it.

For more background on this change, please see this page:
https://wiki.ubuntu.com/X/DisplayConfigGtk