Description of problem:
I have system present in one system group with provisioning add-on entitlement and each time I do some action on that system (e.g. apply some errata and running `rhn_check` on the system), snapshot is created, but it contains "System Group Membership: 1 change" (although I do not do any change in a group membership) in overview snapshot view, but "No group membership differences" in Groups sub-tab.


Version-Release number of selected component (if applicable):
On satellite server:
spacewalk-java-1.2.39-82.el5sat
On client:
rhn-client-tools-1.0.0-61.el6.noarch
rhnlib-2.5.22-10.el6.noarch
yum-rhn-plugin-0.9.1-26.el6_1.1.noarch


How reproducible:
Checked on two Satellites


Steps to Reproduce:
1. Have satellite with synced channel and some system group
2. Register system and add it to the system group
3. Enable provisioning add-on entitlement for that system
4. Schedule errata update and perform it
5. Check snapshot which was just created:
   Systems -> <your_system> -> Provisioning -> Snapshots ->
     -> use latest, "Scheduled action completion: Errata Update" in my case ->
     -> Rollback -> System Group Membership
6. Now still on the page from previous step, click on a sub-tab "Groups"


Actual results:
Rollback sub-tab says "System Group Membership: 1 change"
Groups sub-tab says "No group membership differences."


Expected results:
Both views should be consistent, there were no change