Comment 4 for bug 153918

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.