With upstart and grub2 in Ubuntu 9.10, the way to configure the default runlevel has drastically changed. I'm just writing a quick blog post so I don't forget:
1) Edit /etc/default/grub and make GRUB_CMDLINE_LINUX_DEFAULT look like:
2) Run "sudo update-grub"
3) Edit /etc/inittab, and make it look like:
That should be enough to force Ubuntu 9.10 to boot into runlevel 3