I looked around and found this is an old issue http://forum.linuxmce.com/index.php?topic=1281.0
The problem is that it tries to use the same ip address as my server 192.168.2.1. To stop this at the point where it asks if I want to run a dhcp server I selected no and left the ip setting to 192.168.80. It is still not working though. How can I can stop eth0:0 being created or at least set it to have a sane ip address?
The workaround at the end of this topic http://forum.linuxmce.com/index.php?topic=1281.0
worked for me.
Maybe some additional hints:
I chose to set the network manually, asked the network manager for the current dhcp ip given by my router.
I set this as static ip, and filled in the routers ip as gateway and dns.
I chose no when asked to run a dhcp server, and typed a different three digit ip to my home network (in my case home network has 192.168.1, i wrote 192.168.0).
Installation is still running with no more network problems.
excuse my bad english.