Dual display blanks both screens . Can only see the cursor

I discovered the problem. If I pres the "dual screen" button that comes on my think pad (F7), and I cycle a few times, I get the big screen and the laptop screen to go black with the cursor visible on both screens. Once I get in that mode, I can't get out of it until I reboot.

More observation:

With Compiz:
- I need to have the Laptop screen enabled to keep the dual display active. If I choose to turn off the laptop screen (from the gnome-display settings), both screens go black. Once I get into this settings, there is no coming out of it. If I press "F7" I get to cycle the screen but both screesn will be black. I have to restart GDM to get back into it.

Without Compiz:
- If I do the same as above, the same problem exists but I can re-activate the screens by pressing "F7" to cycle the screen setup.

I think it is partly a compiz thing.

From your latest comment it sounds like a bug in compiz's multihead functionality; refiling to compiz.

I think this is an issue showing up on the DRM layer. This is an intel-driver issue. I don't think it is an intel one any more. https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/529842

Here also a ThinkPad X201 + X200 Ultrabase, running the latest Natty with updates.

I use the 'classic desktop' and no login at boot, and I only see a spinning cursor when the laptop is on the base, the only way out as far as I can see is rebooting and taking the laptop off the docking station.

In principle dual screen functionality works because if you plug in an extra screen through the VGA-out on the laptop itself everything can be set up properly. I can then also achieve my desired configuration, namely the lid of the laptop closed and everything in my external monitor.

I would like to add that in Maverick, I can have the laptop sleeping or off and If I power it using the ultrabase power-on button, the screen stays dimmed and Ubuntu Maverick knows this is just a single screen and it powers the LCD. BTW, the ultrabase has only display port. The laptop has only VGA connector. In other words, this is a regression.

I am starting to think this is *not* bug in compiz but a bug in X or the intel driver.

I switched back to my Mac because I can't work on a 12" screen all day.

Same here. I have a ThinkPad X201 and a Dell 24" display connected via DisplayPort to the X200 UltraBase. I can log into Unity without a problem but when trying to change the resolution, I get a blank screen. But I can "solve" the problem by running this in terminal:

xrandr --output HDMI1 --mode 1920x1080 --preferred --primary --output LVDS1 --off --output DP1 --off

Then the resolution on the external display will change to 1920x1080 and the internal display will shut down.

Have you already tried something like that?

It is not a very good solution, because sometimes I get some minor temporary graphics failures shortly after running this command and I have to run it every time I log in (otherwise one could add it to the list of commands, that are run at startup).

Same here. 11.04 AMD64, Thinkpad X201T + Dell 24" LCD connected to the x200 ultrabase.
No problem at GDM but

in Ubuntu/Ubuntu classic mode
1) Only see a spinning cursor on both screens after login ( if both screens are turn on)
2) Only see a spinning cursor on laptop's screen ( if external monitor is turn off)

in Ubuntu classic no-effects mode
1) Both screens go black ( if both screens are turn on)
2) laptop's LCD display correctly ( if external monitor is turn off)

Fn + F7 has no effects on me.

xrandr -q can detect my DP1 is connecting to the external display, but

xrandr --output DP1 --mode 1920x1200 --preferred --primary --output LVDS1 --off --output HDM1 --off

is not working.

For me it also does not work, when I boot up with both screens turned on. Try booting it up with the ThinkPad's display closed, then it should work.

I get exactly the same problem in an HP dv3 with a fresh-installed Natty. I'm using the proprietary driver from ATI (v11.4) with unity and compiz running. I have radeon and intel_ips modules blacklisted.
When I connect the external VGA monitor it goes to login screen and, if I do login, I get two black screens with a frozen mouse pointer in the middle of both. Booting up with the monitor already plugged in yields the same scenario. Occasionally, I can see a stack trace blinking on and off both monitors. I'll try to get a photo of it.
I also tried booting with recovery's failsafe mode and setup xorg.conf for a dual-head with "$ aticonfig --initial=dual-head -f", but it didn't solve it :(

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to look at all reported bugs in a timely manner. There have been many changes in Ubuntu since that time you reported the bug and your problem may have been fixed with some of the updates. Compiz, in particular, is in heavy development and this bug may have been fixed in the development version of Ubuntu (12.04) if not on your current version. If you are able, it would be of great help if you could confirm if the bug still exists by testing a livecd (available at ubuntu.com). When you test it and it is still an issue, kindly upload the updated logs by running apport-collect <bug #> and any other logs that are relevant for this particular issue. If you are unable to test the development version, please let us know if you are able to reproduce this issue on Ubuntu 11.10.

Thank you for your help and patience.

[Expired for Compiz Core because there has been no activity for 60 days.]

[Expired for compiz (Ubuntu) because there has been no activity for 60 days.]