Just a little comment for somebody that might happen to experience the same bug with XFCE 4.0 package installed from the https://launchpad.net/~xubuntu-dev/+archive/xfce-4.10 (official ppa) on XUbuntu 12.04.
The solution is to go: Settings->Session and Startup->Advanced. Then, under "Shut down", enable the checkbox "Lock screen before sleep".
Just a little comment for somebody that might happen to experience the same bug with XFCE 4.0 package installed from the https:/ /launchpad. net/~xubuntu- dev/+archive/ xfce-4. 10 (official ppa) on XUbuntu 12.04.
The solution is to go: Settings->Session and Startup->Advanced. Then, under "Shut down", enable the checkbox "Lock screen before sleep".