If you try to ban a user via "Ban this user in Mod CP" in their profile it will say it's an invalid ban.
I also noticed that "Ban this user in Mod CP" and the "Edit Ban" button in ModCP goto the same place (modcp.php?action=banuser&uid=2)
I also noticed that "Ban this user in Mod CP" and the "Edit Ban" button in ModCP goto the same place (modcp.php?action=banuser&uid=2)