Under Drupal 6(.4), even if a role has *no* User-Management related permissions, the "User Management" menu does not hide - it still shows, with no items under it. Selecting the menu takes the user to a page that simply states: "You do not have any administrative items."
It seems to me, that the menu simply should not be present.
To reproduce, using a brand-new D6.4 installation:
1) login as the site's superuser, and create a new role - name it anything you wish
2) In the 'permissions' page for the new role, make sure the role has *no* user management permissions - under "user module", deselect everything.
3) create a new user for the site, and give this user the newly created role
4) log out as the superuser, and login as the new user, with the new role
5) notice that under 'Administer', you still have "User Management" - clicking it will take you to that silly page that states that you have no administrative items...
This is a *very* annoying bug. I do *not* wish the "User Management" menu to be displayed for certain roles - ie., 'site editors', whose function is simply to add and edit content to the site.
FAILED: [[SimpleTest]]: [MySQL] 18,916 pass(es), 24 fail(s), and 2 exception(es).
Unable to apply patch menu_group_item_nice_little_query.patch
Unable to apply patch drupal.empty-categories.92.patch
Failed: 14541 passes, 2 fails, 0 exceptions