*Turn off your Visual Effects and the dual/extending monitor works!!
Well this is probably nothing much for most people. It is, to me, that the dual monitor thingy is finally working. The thing is, I am using two monitors here and Ubuntu 9.10 RC’s did not support them to work side by side. Now it is and I can type on one screen a search on the other. Guess what? 
Happy as a clam!!
[I went to my office and did the same thing on my TravelMate 3000 (I have a 3010 at home) and it didn't work. Turned out that it worked right after I changed the Visual Effects to None. So, maybe it's been working? Stupid me/Ubuntu!]
hah
November 3, 2009 at 02:56
you must not be using ATI then. NVIDIA will of course work. ATI support is crap.
polochen
November 3, 2009 at 22:35
nah…Acer wouldn’t be cool enough to give you chips nice enough to have those kind of problems. But Ubuntu 9.10 is really cook and this 6 months release schedule will push it top over Windows.
Alex G
February 24, 2010 at 18:26
You are a Star !!!! Thank you. I have duel screen setup with a ATI card. I Had no background showing, and the live CD was working without any problems, until I installed it on my hard drive. Thanks Again !!
(Using Ubuntu 9.10)
Alex
recken
March 24, 2010 at 03:41
Thanks!
Using a second 1440×900 monitor on a 1024×768 laptop with built in Intel on Ubuntu 9.10. Couldn’t figure it out. Even tried editing the xorg.conf file directly (what a disaster).
In the end I only needed to turn of desktop effects.
Xenia
March 28, 2010 at 15:44
I tried this neat trick, and it works! My next step is to find out how to make my external monitor the primary one instead of my laptop.
Thanks for sharing this tip!
polochen
April 18, 2010 at 07:24
Did you get it to work?