udevadm trigger is not permitted while udev is unconfigured

[bries]

Hi,
I use Parallels 5 for Mac (10.6.4). I started my Ubuntu 10.4 virtual machine and it didn't load the Ubuntu Gnome desktop. In stead I did get a command line prompt. I could login with normal username and password, rebooted again, but same result.
I tried to update the system with:

sudo apt-get update
sudo apt-get upgrade

The update went smooth, but after rebooting the system I get the message:
udevadm trigger is not permitted while udev is unconfigured

I tried to load a Live CD, but I can't boot it.
Where do I go from here?
Any advise much appreciated,