I had just installed Ubuntu 11.10 on my MacBook Air, and have a lot of problems. I used this tutorial, after executing script and rebooting some problems were solved, but now I have completely not working touchpad, keyboard & screen backlight works incorrect (screen brightness is not 100%, but it is 100% in settings, keyboard backlight turns on/off randomly). How to fix it? P. S. Script said that it's no such file or directory for some .icc file. Google says, that I should copy it from Mac OS X drive, but I completely replaced it with Ubuntu.
It's more robust (and less likely to cause issues in the future) to use the latest stable Ubuntu version, which is 12.04 (11.10 causes so much problems for Macs...). You should find your trackpad, keyboard, and backlight working properly.