Permissions issue in "Modify Category" screen-My Organization

[anovak]

When I go into Modify Catagory screen and modify the "My Organization"
category, there are two similar groups listed in the "Users and groups
with permissions" list -- "Administrator" and "Administrators".

When I select "Administrator", the permissions list ("Adjust actuals",
etc.) is readily changeable.

When I select "Administrators", the permissions list is greyed out and
you can't change anything -- it actually shows no Allow or Deny
checkboxes checked.

What's the deal?

Thanks,
Andy