Tried to run an up2date command on a server and received the following:
[root]# /usr/sbin/up2date -l
Error Message:
Please run rhn_register (or up2date --register on Red Hat Enterprise Linux 3 or later)
as root on this client
Error Class Code: 9
Error Class Info: Invalid System Credentials.
Explanation:
An error has occurred while processing your request. If this problem
persists please enter a bug report at bugzilla.redhat.com.
If you choose to submit the bug report, please be sure to include
details of what you were trying to do when this error occurred and
details on how to reproduce this problem.
[root]#

This server was registered already with our satellite server.... I then tried to re-register the server as suggested and received the following:
[root]# rhnreg_ks --activationkey "d2defa494dde54cef09be8bc8a666d4a" --serverUrl http://mural18.cmg.convergys.com/XMLRP
This system is already registered. Use --force to override
[root]#
[root]#
[root]# rhnreg_ks --activationkey "d2defa494dde54cef09be8bc8a666d4a" --force --serverUrl http://mural18.cmg.convergys.com/XMLRP
An error has occurred:
exceptions.AssertionError
[root@cvgpodev1 root]#

My only suggestion is to remove this system from the satellite server and rerun the register from the server. Something seems wonky probably on the server side or a local config is screwed up somehow.

What command do you use to un-register a server from the satellite server ?