This is nice guide and today I tried to install a Ubuntu 6.10 to a existing partition (which was used to test Vmware Player but I found Vmware Player is not my cup of tea since I prefer multi-boot) from a chroot environment under Ubuntu 6.06 LTS.
A fast mirror is nice to have in this case. For me I use either the default Singapore mirror (http://sg.archive.ubuntu.com) or the Australia mirror (ftp://mirror.pacific.net.au).
I manually installed the following file, there may be new versions when you read this.
After that, I followed the guide and I have a working base installation in less than 20 minutes.
I found /etc/resolve.conf
and etc/hostname was already set up properly for me.
After editing the grub.conf inside Ubuntu 6.06 LTS (I mainly use it along with 7.10) and rebooting, I ran the following two commands and then I had a almost fully working system. Strangely sound did not work under Gnome until power-down and then cold-boot the computer.
sudo apt-get install ubuntu-standard
sudo apt-get install ubuntu-desktop