You DHCP once in stage1. Click the additional repos button in stage 2, and it'll prompt you to make sure you have a working network connection, and try to DHCP on the same NIC again. Then it'll hang forever. Should probably check if the NIC is already up and skip the prompt if so.
Still happening in anaconda-11.2.0.40-2 (today's rawhide and the current Test3 candidate tree). In fact, if you hit the "Add additional software repositories" button while doing an NFS install, we appear to lose the NFS server and hang completely. The last anaconda log lines are: moving (1) to step reposetup moving (1) to step basepkgsel moving (1) to step tasksel The last system log lines are the nic going down and coming back up, and then: nfs: server hostname.localdomain not responding, still trying and that's it.
*** Bug 234263 has been marked as a duplicate of this bug. ***
*** Bug 235814 has been marked as a duplicate of this bug. ***