Description of problem:
After updating the yum-rhn-plugin to 0.5.4-22.el5_7.1, when you execute pup (Applications -> System Tools -> Software Updater) you will get a registration window even though the system is already registered, saying that "Software updates have already been configured for this system". Wether you re-register the system again or refuse to do so, the Software Updater will eventually open but showing "There are no updated packages currently available for your system"

Version-Release number of selected component (if applicable):
yum-rhn-plugin0.5.4-22.el5_7.1

How reproducible:
Always

Steps to Reproduce:
1. Update yum-rhn-plugin to 0.5.4-22.el5_7.1
2. Applications -> System Tools -> Software Updater
3.
  
Actual results:
You will get a registration window even though the system is already registered, saying that "Software updates have already been configured for this system". Wether you re-register the system again or refuse to do so, the Software Updater will eventually open but showing "There are no updated packages currently available for your system"

Expected results:
You get the list of available packages for update.

Additional info:
- You can still update through "yum update", trouble-free.
- Downgrading the yum-rhn-plugin package fixes the issue immediately.