Removing Registered group from a user doesn't work as expected

• Error
• Usability

This has also been reproduced on the http://demo.opensourcecms.com site.

I created a user. Then I'm trying to remove the "Registered" group from the groups associated to that particular user. When I click on the little x next to the group it disappears from the user's groups. Then I created a group named "blocked". This group only inherits from the anonymous group. It is created basically to prevent a user from having more permissions than an anonymous user, without removing the account (in order to reactivate the permissions at a later time). What I actually want to do is to deactivate some accounts and reactivate them later. So limiting the permissions to that of an anonymous user seemed an appropriate course of action. After removing the "Registered" group from the user's list, I assign him the blocked group only. This blocked group include the anonymous group and that's it. But, when I go to see the blocked group's permission(it has none of its own), I see some permissions inherited from the anonymous group (which is what I asked for) but I also see the tiki_p_edit permission inherited from the "Registered" group (which is NOT what I asked for). So it seems to me that when you have a user, it belongs necessarily to the registered group. And when you remove that group from the user's group list, it doesn't seem to have any real effect aside from not showing that group in the list. It would be interesting to remove that registered group from some users to deactivate their account temporarily. In any case this seems a bug, either removing Registered should have the expected effect, or it should not be possible to remove that group at all. I would opt for the first alternative.

Related:
http://dev.tikiwiki.org/tiki-view_tracker_item.php?itemId=1124

This bug has been demonstrated on show2.tiki.org

Please demonstrate your bug on show2.tiki.org