I guess it would all depend on what ISO you are using then because I built a new system this weekend using 'CentOS-6.0-x86_64-minimal.iso' and upon reboot I never get anything for first boot. I had to edit my configuration files by hand to get the system online.
NetworkManager is a POS and should be dropped. Of course this is my opinion and I stand by it.
I wouldn't care. I can go back to the old way of doing things. But I have too many Windows admins that dabble in the Linux space (CentOS really) and I really don't need the whining. === Al