Using Unity on Xmir a Dell Latitude E6410 does not suspend when the lid is closed

[Walter Garcia-Fontes]

When the lid is closed the system does not suspend any more when I switch to using Unity on Xmir. If I start Unity just on plain X the system suspends normally when the lid is close. The system suspends normally (using Xmir) if I click "suspend" from the upper panel menu.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: unity-system-compositor 0.0.1+13.10.20130903-0ubuntu1
ProcVersionSignature: Ubuntu 3.11.0-5.11-generic 3.11.0
Uname: Linux 3.11.0-5-generic x86_64
ApportVersion: 2.12.1-0ubuntu3
Architecture: amd64
Date: Mon Sep 9 07:02:58 2013
GraphicsCard:
 Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:040a]
InstallationDate: Installed on 2012-05-31 (465 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
LightDMLog: Error: [Errno 13] S’ha denegat el permís: '/var/log/lightdm/lightdm.log'
MarkForUpload: True
SourcePackage: unity-system-compositor
UnitySystemCompositorLog: Error: [Errno 13] S’ha denegat el permís: '/var/log/lightdm/unity-system-compositor.log'
UpgradeStatus: Upgraded to saucy on 2013-09-06 (2 days ago)
version.libdrm: libdrm2 2.4.46-1
version.lightdm: lightdm 1.7.12-0ubuntu1
version.mesa: libegl1-mesa-dev 9.2-1ubuntu1