Xorg crashed with SIGABRT in RRCrtcDetachScanoutPixmap()

[Anubis]

It is happening all the time after log-in to the desktop. It just popups this error message.

ProblemType: Crash
DistroRelease: Ubuntu 14.04
Package: xserver-xorg-core 2:1.15.0-1ubuntu7
ProcVersionSignature: Ubuntu 3.13.0-18.38-generic 3.13.6
Uname: Linux 3.13.0-18-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14-0ubuntu1
Architecture: amd64
CrashCounter: 1
Date: Tue Mar 25 10:55:59 2014
ExecutablePath: /usr/bin/Xorg
InstallationDate: Installed on 2014-03-19 (13 days ago)
InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140225)
ProcCmdline: /usr/bin/X -core :1 -seat seat0 -auth /var/run/lightdm/root/:1 -nolisten tcp vt8 -novtswitch
ProcEnviron:

Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 ?? () from /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so
 ?? () from /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so
 ?? () from /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so
 ?? () from /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so
 RRCrtcDetachScanoutPixmap ()
Title: Xorg crashed with SIGABRT in RRCrtcDetachScanoutPixmap()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

[Apport retracing service (apport)]

StacktraceTop:
 ?? ()
 ?? ()
 ?? ()
 ?? ()
 ?? ()

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.