Thinkpad X201 external DP monitor goes black if internal display is disabled with Monitors applet

[Adam Thompson]

I think this is related to #749817, but perhaps a bit more specific.
Running up-to-date 11.04 as of Sat May 7 23:59:32 UTC 2011.
Using the Monitor applet, if I disable the internal display, the external DisplayPort (DP) display also blanks and goes to sleep.
The only error I see is in dmesg:
        [date&time] [drm:intel_dp_complete_link_train] *ERROR* failed to train DP, aborting

Using Fn+F7 sometimes works to restore the display, but more often gives me two black screens with a mouse pointer but no X clients painted. I can use ctrl+alt+f1 to switch back to the text console, alt+f8 to switch back to X and the same situation continues: two black screens, mouse pointer, nothing else. Note that the mouse pointer appears to correctly switch between pointers (arrow vs. insertion caret vs. resize handles) as it passes over various black areas of the screen, and the clients are still running perfectly OK, they just don't display.

When Fn+F7 fails to restore the display, I get the above error logged again.

Yet, using "xrandr --output LVDS1 --off" to accomplish my goal works perfectly with no side effects.

Could the problem somehow be in the Monitors applet???

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-8-generic 2.6.38-8.42
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: athompso 1684 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf2520000 irq 44'
   Mixer name : 'Intel IbexPeak HDMI'
   Components : 'HDA:14f15069,17aa2157,00100302 HDA:80862804,17aa21b5,00100000'
   Controls : 12
   Simple ctrls : 6
Card29.Amixer.info:
 Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw 6SHT32WW-1.13'
   Mixer name : 'ThinkPad EC 6SHT32WW-1.13'
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card29.Amixer.values:
 Simple mixer control 'Console',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Sat May 7 18:53:20 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
MachineType: LENOVO 2985EYU
ProcEnviron:
 LANGUAGE=en_CA:en
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-2.6.38-8-generic root=UUID=a3148d82-bfc6-4b7a-8eb7-862ee9ef6654 ro rootflags=subvol=@ quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-8-generic N/A
 linux-backports-modules-2.6.38-8-generic N/A
 linux-firmware 1.52
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/24/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 6QET64WW (1.34 )
dmi.board.name: 2985EYU
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:bvr6QET64WW(1.34):bd02/24/2011:svnLENOVO:pn2985EYU:pvrThinkPadX201Tablet:rvnLENOVO:rn2985EYU:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2985EYU
dmi.product.version: ThinkPad X201 Tablet
dmi.sys.vendor: LENOVO