Group Roles are missing in existing groups

1. Go to a group and view their members page. Such as: http://www.curriki.org/xwiki/bin/view/Group_CurrikiLeadersGroup/Members
2. Then click on: Manage Roles http://www.curriki.org/xwiki/bin/view/Group_CurrikiLeadersGroup/ManageRoles

Bug
In both cases the default roles are missing. This is not unique to this group as examples can be found through out the site. Additionally, this problem does appear to be happening for newly created groups.

Could this bug be related to the hardware problems we recently had?

I cannot repeat the problem on Next.

David, please take a quick look, then pass on to Ludovic if it is nothing obvious.