lightdm display freezes

[Frederik Hanghøj Iversen]

So, my guess is that the issue is with the display manager, but to be honest I'm not entirely sure.

My issue is that sometimes the display freezes. Nothing moves on the screen yet the mouse and keyboard is still activated and - i pressume - everything else is running smoothly. I know this because when it happens I jump back and forth between one of the other tty's (with Ctrl+Alt+f{1..6}] and when the display is refreshed (possibly by forcing the screen to be redrawn, e.g. clicking the super-key) eveything looks ok.

I'm on 14.04

$ lspci
00:00.0 Host bridge: Intel Corporation Haswell-ULT DRAM Controller (rev 09)
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 09)
00:03.0 Audio device: Intel Corporation Haswell-ULT HD Audio Controller (rev 09)
00:14.0 USB controller: Intel Corporation Lynx Point-LP USB xHCI HC (rev 04)
00:16.0 Communication controller: Intel Corporation Lynx Point-LP HECI #0 (rev 04)
00:1b.0 Audio device: Intel Corporation Lynx Point-LP HD Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 1 (rev e4)
00:1c.2 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 3 (rev e4)
00:1c.3 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 4 (rev e4)
00:1c.4 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 5 (rev e4)
00:1d.0 USB controller: Intel Corporation Lynx Point-LP USB EHCI #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation Lynx Point-LP LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation Lynx Point-LP SATA Controller 1 [AHCI mode] (rev 04)
00:1f.3 SMBus: Intel Corporation Lynx Point-LP SMBus Controller (rev 04)
01:00.0 3D controller: NVIDIA Corporation GK107M [GeForce GT 750M] (rev a1)
04:00.0 Network controller: Intel Corporation Wireless 7260 (rev 73)
05:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device 5287 (rev 01)
05:00.1 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 14)

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: lightdm 1.10.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
Uname: Linux 3.13.0-29-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
Date: Sun Jun 15 11:12:20 2014
ExecutablePath: /usr/sbin/lightdm
InstallationDate: Installed on 2014-06-04 (10 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
LightdmConfig:
 [SeatDefaults]
 autologin-guest=false
 autologin-user=fredefox
 autologin-user-timeout=0
 autologin-session=lightdm-autologin
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)