maybe someone finds this useful...
When chaning the networking type of a VM the network interface card is renamed in Linux. So you end up with eth1 or eth2 instead of eth0.
On most modern Linux distributions these interface names are handled by the udev daemon. I only had to edit /etc/udev/rules.d/30-net_persistent_names.rules in my SLES10 guest accordingly et voila I had back my beloved eth0 network interface after a reboot!
so long,
Lars.