The UCP and ACP create different log entries when an administrator activates an user account. If an administrator activates an user through the ACP both a `user` and `admin` log are created.
However in includes/ucp/ucp_activate.php only a log entry is created when the user re-acivates his account after a password change.
However when admin activation is enabled the link the administrator receives points to the ucp activation module instead of the acp one. Therefore there are no logs of the user activation.