System doesn't shutdown when I select in qbittorrent the option of shutdown after finish download

[DAVID AARON GARCIA TERUEL]

I've already used qbittorrent with Unity and it doesn't present this problem: the system shutdown normally if I select the option "after the download finish= shutdown". I reported the bug to qbittorrent. The link of the issue is this:
https://github.com/qbittorrent/qBittorrent/issues/2575#issuecomment-74669677
Apparently the conflict is with the light-locker. Please fix it or suggest me what to do.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: qbittorrent 3.1.8-2
ProcVersionSignature: Ubuntu 3.13.0-48.80-generic 3.13.11-ckt16
Uname: Linux 3.13.0-48-generic i686
ApportVersion: 2.14.1-0ubuntu3.8
Architecture: i386
CurrentDesktop: XFCE
Date: Sat Apr 4 10:01:09 2015
InstallationDate: Installed on 2015-03-31 (3 days ago)
InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Release i386 (20140416.2)
ProcEnviron:
 LANGUAGE=es_HN:es
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=es_HN.UTF-8
 SHELL=/bin/bash
SourcePackage: qbittorrent
UpgradeStatus: No upgrade log present (probably fresh install)