Alternative solution that cross my mind is to use NVIDIA graphic setting software. There should be a setting about multiple monitor there. I don't have NVidia card here, so I can't guide you. Make a backup of your /etc/X11/xorg.conf first, just in case.
I took your suggestion and ran with it. I did (after 2 1/2 hours of fighting with utils that don't quite work right) get the outcome I was looking for.
First, I saved the original /etc/X11/xorg.conf file as /etc/X11/xorg.conf.orig for "anti-borkage" protection.
Then I fired up the NVIDIA X Server Settings window. It said both screens were deactivated and named DFP-0 and DFP-3 and it had DFP-3 to the right of DFP-0 (backwards).
After several iterations and trials I figured out that you have to enable the screens first to be allowed to move them. After more trials I figured you need to enable the first one (either one) and when you enable the 2nd one you want "Twinview". This then allows you to move the screens (only the movements have to be in a specific order and direction to be able to swap the two monitors - took some trial and error to figure this out as well). I then set both positions to "absolute" (you need to click on the "Advanced Settings" to see this). I also set DFP-0 as the primary screen for the X Screen. I then tried to "Save to X configuration file". Now the fun starts. It now complained that there were insufficient privileges to write the xorg.conf file. Going to /etc/X11/xorg.conf the permissions were set to 664. Ok, I'll play hardball and went in as root and changed them to 777. Tried to save the file again and now it complained that it had no privileges to write xorg.conf.backup. The file doesn't even exist! So I made a copy of xorg.conf and called it xorg.conf.backup. I even did a chmod 777 to it to be sure. Tried to write the file again and it still complained about the backup file. ARHG! Getting nowhere fast.
Well, after playing with it for a while longer I discovered the it was NOT writing to the xorg.conf file at all
no matter what I did (either in append to existing file or not). So, I did the complete setup so it was correct, then did a preview of the changes, copied them into the cut buffer and using nano edited the xorg.conf file (deleted the ENTIRE contents first then pasted the cut buffer). Saved it and rebooted (for the n'th time). It worked!
Phew..... Then went back and corrected the file permissions to 664 on the xorg.conf files (and their derivatives). And deleted the xorg.conf.backup file.
So the "NEW final" xorg.conf file now looks like:
# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 304.51 (email@example.com
) Thu Oct 11 02:30:43 EDT 2012
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
Option "Xinerama" "0"
# generated from default
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
# generated from data in "/etc/sysconfig/keyboard"
Option "XkbLayout" "us"
Option "XkbModel" "pc105"
# HorizSync source: edid, VertRefresh source: edid
ModelName "Acer H243H"
HorizSync 31.0 - 83.0
VertRefresh 56.0 - 76.0
VendorName "NVIDIA Corporation"
BoardName "GeForce GTX 560 SE"
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "DFP-0"
Option "metamodes" "DFP-0: nvidia-auto-select +1920+0, DFP-3: nvidia-auto-select +0+0"
So there appears to be "multiple bugs" in the user interface for setting up dual monitors (KDE4 and/or PCLOS, I'm not sure).
Definitely not a mod for the faint of heart or someone who has very little patience...
And who the heck is (firstname.lastname@example.org)
? ---> The OS gurus STILL have their work cut out for them.. <---
Many thanks to Ferry_th (et. all) for your helpful assistance!