Bug#582292: Confirmed here

[Fabricio Rocha]

Same happened here and I spent some hours to get to an X screen again. 
My USB external CD-RW drive can't be seen by any CD writer software 
(another bug), and after some googling I tried to ensure that hal and 
udev were working. In the Gnome's Services dialog, udev and udev-mtab 
appear UNticked (but "ps aux | grep udev" shows "udevd --daemon" three 
times for the root user).

Ticking the udev checkbox caused gdm to lock miserably in the following 
boot. The USB mouse could get live again after being disconnected and 
reconnected, but the keyboard would not work by any means. With the 
mouse working again, I could choose to suspend the computer, then right 
after waking it up (which does not bring the X screen automatically, but 
a blinking cursor instead -- would this be another bug?) I could do 
Alt+F1 and edit gdm.conf for enabling autologin; so I could go have 
Gnome's Services dialog again for unticking the "udev" checkbox.

If this info could be helpful, I use kernel 2.6.32.4 customized for the 
Acer Aspire One; udev 154-1; gconf2 2.28.1-3 and lots of Gnome 2.30 
parts from unstable.

Regards and good luck!

Fabricio Rocha
Brasilia, Brasil