The networking configuration (ie. /etc/resolv.conf, /etc/hosts) is not setup anymore for commands which run inside %post. This was working in 6.0, it's broken now.
Not quite sure what you are reporting here; /etc/resolv.conf and /etc/hosts are setup during the install and should have no correlation to commands in the %post section unless you are explicitly changing them in the %post section. Please provide more details of the problems that you are seeing.
Closing due to lack of activity.