I'm a little new to this forum, so I'm sorry if this is in the wrong place.
I'll make this quick. Whenever I try to extend my desktop to the left using an external monitor 95% of the time KDE will completley crash. By Completely crash, I mean it turns my screen black, or it shows my desktop misaligned on both monitors, and everything becomes unresponsive forcing me to hard restart.

I am trying to connect a 1600x1900 monitor to my 1366x768 laptop. I understand that KDE would rather have some sort of even ratio, but not in my case. It actually works great if I try to extend it to the right or clone the monitors, its only when I try to extend it to the left where it crashes. Occasionally it does work, but most of the time it just crashes. When I set both monitors to 1024x768 it works, but I rather not since it stretches everything out. I did not touch the xrandr config file, since I assumed that adjusting the display settings in the KDE enviroment would do that for me.

I should also note that I am able to extend the desktop to the left flawlessly when I'm running Windows 7. I've seem to be having this problem also with GNOME, LXDE, and Ubuntu (although I was able to force it by changing the primary monitor. I tried the same with KDE but it didn't work.)

Any help would be appreciated.

Could you please specify which KDE version you are using?

Also, tell us more about your graphic card, graphic driver, and Xorg version.

Since you have the same problem in GNOME and LXDE I would assume that the problem lies in Xorg.

I am running KDE version 4.8.2, and Xorg version 1.12.1

My "graphics card" is the "Intel HD Graphics family" built into their i5 processors.
I think my video driver is whatever is included with the package "xf86-video-intel," or "intel-dri", i'm not sure. Is there a way to show what graphics driver I have without having to scroll through all installed packages?

I just tried extending the destkop without running KDE, only X, and I get the same result, so I think your right Hans, this is a problem with X, not KDE.

You should be able to set the primary monitor under KDE, in System Settings.
Have you tried this workaround under just X?

Changing the primary monitor to the external monitor was actually the first thing I tried, since it sortof worked when I had ubuntu.
It just crashes KDE when I try that, but when I do it in just X, it just keeps flashing my screens on and off in an endless loop, almost like its trying to set my monitors but runs into an error and restarts.

Also should note, when I start the computer with the monitor plugged in, it clones and sets the resolution of both monitors to 1024x768. If I change any sort of display setting it crashes.

EDIT: Just curious, am I the only one having this issue?

your distro is ubuntu? what version?

No, I'm running Arch Linux, which I think opens up an even bigger can of worms because since I had to set up EVERYTHING by hand so a whole number of things could be wrong. But if the crash was caused by a noob mistake in a config file, I would think the monitors wouldn't work at all. Plus I'm having the same issue with other distros and enviroments, like LXDE and GNOME,

Ubuntu wouldn't let me extend my desktop to the left, theres not even an option for it in the display options. I had to force it using xrandr to set the VGA monitor as the main monitor, thus having the laptop screen as the extended desktop. The only issue is that 50% of the time ubuntu won't boot, and when it does I can't disconnect the monitor or else my screen turns into a bunch of colored lines, forcing me to hard reset.

I installed Linux Mint to see if the problem still occurs on a different computer this time, and it still does. So I ruled out this being a hardware/compatibility issue. Or i can just be the unluckiest man alive and have the only 2 computers that have this issue. Seriously, does anyone else have this problem?

I got some new information that might really help you guys out.

In KDE (I haven't tried it in a GNOME enviroment yet) under display settings, you can set the monitor positions to a specific coordinate (KDE calls this the "Absolute" position). If the X or Y coordinates are negative (i.e to the left/down) it crashes the enviroment. However if they are any other number, it works.

Depending on the coordinates (I used 1,1, -1,1, and 1,-1, default would be 0,0 [that clones the monitors] and extending the VGA monitor to the right would be in my case 1366,0), it might look really awkward but it works.

EDIT: When I change the position of my laptop monitor to 1600,0; which would move my laptop screen to the right, making my VGA screen the left monitor, it crashes the same way, even though there are no negative #s that I am aware of involved. So I'm once again stumped.

Have you tried using manual xrandr commands to achieve this, to rule out bugs in KDE itself (ie. to confirm the issue lies in the graphics driver or X)?

Sorry about the LONG wait, had finals to study for and work...

Anyway I just gave up, the problem wasn't that big to begin with, and I just simply moved my monitor to the right of my computer to deal with it.

But recently KDE just decided to stop working all together (I'll probably have to make a new thread on that since I can't deal with it now. Basically I boot into KDE and it hangs, then I hit Ctr Alt F1-6 and the screen is filled with "READ FPDMA QUEUED, DRDY ERROR" and "I/O Error," but I doubt its the hard drive failing since it boots perfectly on any other enviroment, it only does this on KDE even after a complete reinstall.) I installed cinnamon, and when I used the KDE display settings to once again extend my desktop to the left it worked with no fuss whatsoever. I was even able to change my primary monitor to the left as well. I retried several times and it worked everytime. Only problem is that I have no clue why, and I like knowing why so I can deal with it if the problem shows up again

Unfortunately those I/O and FPDMA errors are sourced from the kernel - and are disk/kernel related according to https://bugs.launchpad.net/ubuntu/+sour ... bug/550559

I find it very unusual that KDE is the only software on your system that triggers this behaviour however.
It is good to know that the multi-screen configuration tools work properly though.

I have this exact problem. My system is a Dell Latitude E5400 laptop (Intel GM45 graphics chipset). Under every Linux and BSD distribution (PC-BSD, Ubuntu, Fedora, Linuxmint (my personal favorite ), and FreeBSD)I have tried including all desktop environments (KDE, GNOME, LXDE, Xfce, Cinnamon, etc.) the system crashes when trying to change the external monitor configuration. I have a docking station with a DVI 1920 x 1080 monitor and a VGA 1280 x 1024 connected to it. Without any sort of extended monitor configuration; it works. If the desktop is extended, I am forced to leave the positioning of the VGA monitor (set as default display) as is. Any sort of moving it around causes the above crash. You will be happy to know that you and I are not alone in this bug:

http://ubuntuforums.org/showthread.php?t=1305919&page=5
http://forums.linuxmint.com/viewtopic.p ... 8&p=594252
http://forums.opensuse.org/english/get- ... ution.html

and these are just a few of the Google hits available. With the above information, it would seem that this is an X server problem - not a kernel or desktop environment bug. I have found a few supposed solutions and am in the process of trying them. I will post back as soon as I have the results of these solutions.