Description of problem:
firstboot doesn't allow rhn registration, combo box at initial rhn page is not available anymore, pressing Forward button will skip it entirely.
Version-Release number of selected component (if applicable):
This is more likely an issue of rhn-client-tools, rhn_register is missing initial combo box as well, however it is working properly even without that, therefore reporting against firstboot
Sorry, this is caused by unavailable network (as it is described on screenshot). I will close it soon as a duplicate of real issue (and next time will better read all messages).
*** This bug has been marked as a duplicate of bug 623937 ***