freezes, I have to start gdm manually?

[q0k]

After up upgrade from 11.04 to 11.10, the system freezes after saying
'waiting for network configuration' and 'booting without network
configuration' but a manual 'sudo /etc/init.d/gdm start' in tty causes
the login screen to appear.

I already did http://uksysadmin.wordpress.com/2011/10/14/upgrade-to-ubuntu-11-10-problem-waiting-for-network-configuration-then-black-screen-solution/
and rebooted.

How can I troubleshoot this?

How can I check what it tries to start onboot? It should be gdm.