Comment 67 for bug 416073

Have you tried installing 2.4 from Jaunty and then dpkg the 2.6 version downloaded from here

http://www.intellinuxgraphics.org/

?

You should force the install ignoring all dependencies. i.e.: dpkg --force-all -i *xorg_intel_driver.deb*

(I apologize for the rather redundant post here)