Sidebar and menu bar suddenly disappear from screen

[Mosh Aharoni]

While surffing the net with no video or audio application running, both menu and side bars disappear. Terminal wo'nt open as well using CTRL+ALT+T.
Tty terminals open normaly.

a : sudo restart lightdm reloaded the desktop and everything returned to normal. It has happend to me twice at least during the last 5 days. Using Ubuntu 13.10 for about a week now.

Thanks.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: bamfdaemon 0.5.1+13.10.20131011-0ubuntu1
ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
Uname: Linux 3.11.0-12-generic i686
ApportVersion: 2.12.5-0ubuntu2.1
Architecture: i386
Date: Sat Nov 2 18:19:34 2013
InstallationDate: Installed on 2012-12-17 (319 days ago)
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
MarkForUpload: True
SourcePackage: bamf
UpgradeStatus: Upgraded to saucy on 2013-10-26 (7 days ago)