External monitor not recognized properly

I have an external monitor attached to my Lenovo X200s through a docking station (via a HDMI (monitor) -> Displayport adapter (Docking Station)). This setup was working fine until I just updated my Ubuntu 13.04 install. Now, Ubuntu doesn't recognize the monitor properly (see screenshot) and nothing is displayed on the external monitor. Also, even if I unplug my monitor, the display options still think that there is an unknown monitor attached and the system behaves as if I'm using 2 monitors. Curiously, if I attach my monitor via VGA (also through the docking station or directly on the computer), everything seems to work properly.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: xorg 1:7.7+1ubuntu4
ProcVersionSignature: Ubuntu 3.8.0-13.22-generic 3.8.3
Uname: Linux 3.8.0-13-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.9.1-0ubuntu1
Architecture: amd64
CompizPlugins: [core,composite,opengl,decor,grid,resize,mousepoll,move,wall,compiztoolbox,gnomecompat,vpswitch,imgpng,place,regex,unitymtgrabhandles,wobbly,animation,fade,session,scale,expo,ezoom,workarounds,unityshell]
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Sun Mar 17 10:12:56 2013
DistUpgraded: 2013-03-16 08:21:38,649 DEBUG enabling apt cron job
DistroCodename: raring
DistroVariant: ubuntu
DkmsStatus: i915-3.6-3.5, 0.033.2: added
EcryptfsInUse: Yes
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:20e4]
   Subsystem: Lenovo Device [17aa:20e4]
InstallationDate: Installed on 2012-04-26 (324 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MachineType: LENOVO 746988G
MarkForUpload: True
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-13-generic root=UUID=eb242438-679c-4ddb-8fce-4efcc9ee587b ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: Upgraded to raring on 2013-03-16 (1 days ago)
dmi.bios.date: 01/12/2010
dmi.bios.vendor: LENOVO
dmi.bios.version: 6DET62WW (3.12 )
dmi.board.name: 746988G
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6DET62WW(3.12):bd01/12/2010:svnLENOVO:pn746988G:pvrThinkPadX200s:rvnLENOVO:rn746988G:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 746988G
dmi.product.version: ThinkPad X200s
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.9~daily13.03.08-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.42-0ubuntu2
version.libgl1-mesa-dri: libgl1-mesa-dri 9.0.3-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental 9.0.3-0ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 9.0.3-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.13.3-0ubuntu2b1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2b2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.1.0-0ubuntu1b1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.21.4-0ubuntu1b1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.6-0ubuntu3b1
xserver.bootTime: Sun Mar 17 10:08:55 2013
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.13.3-0ubuntu2b1
xserver.video_driver: intel