I run Ubuntu 14.04 Gnome Desktop with two displays. After startup, the two displays work, but they are not at the right position. I need the left one on the right and vice-versa.
I use the display manager to change and apply changes, but it won't persist after reboot.
I already tried modifying .config/monitors.xml, swapping the <y> values of both monitors, but it didn't work. 
Any idea how to persist the configuration without using a custom xrand command ?
Here is the configuration I want:
Screen 0: minimum 320 x 200, current 3840 x 1200, maximum 16384 x 16384
DisplayPort-0 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x 324mm
     1920x1200      60.0*+
     ...
VGA-0 disconnected (normal left inverted right x axis y axis)
DVI-0 connected primary 1920x1200+1920+0 (normal left inverted right x axis y axis) 518mm x 324mm
     1920x1200      60.0*+
     ...
But upon startup the left inverted right are swapped.
 
     
    