HELP! I cannot setup a /29 subnet on Cloudmin (Hetzner Servers)

HELP! I can’t setup networking in Cloudmin, using CENTOS 5.8 64bit on Hetzner servers!

I have tried several How-To’s found on the net however everytime I get a server that becomes completely inaccessible and I have to ask the support to reinstall the OS!

Can some one give me some help on this?
Basically I am setting up the server, I go through the Cloudmin guide and I reach the point where I create the guest VMs. All well up to here but when I try to start them up, the VMs cannot be pinged. When I access them via Graphical Console I see that the system is wokring but there is no route to the internet. I cannot even ping the host machine IP.

I have one stati IP + a /29 subnet and I am trying to use the bridge setup however with no luck.
Please helppppppppp!