Proxmox 1.9 to Proxmox 3 - No Console / No Kernel

Hi!

I've been restoring a vzdump backup in order to make the transition from proxmox 1.9 to proxmox 3.
However, in the new environment my VMs don't seem to start - I think they can not load the kernel.
When I open the console after booting it says "no processes on this runlevel left" and while booting it prints out messages like "could not load /lib/modules/.../modules.dep"
My machines are using the "debian-6.0-standard_6.0-2_amd64" template

Edit: The first host is using "Linux 2.6.32-4-pve" while the new host is using "Linux 2.6.32-20-pve" - Is there any way to downgrade or upgrade the containers?

How can I fix this?

kind regards
s1ck