I made a small fix, that positions the GUI Elements in the centre screen.
While the GUI reffers to a 1024x768 resolution and I found no way to change this I simply divide the Left attribute of the elements by 3 and added the ammount of the left monitor.
The Problem on this fix is, that Text stays also stretched, what means that some text will not be displayed.
But I find this a better bug that have all the GUI Elements on 3 different screens and in triple width.
This only affects the Elements that annoys most while playing. Health/Mana/Endurance/Dialogs.
This not change anything to the mainmenu/loadingscreens/videos/map/inventory/loot/etc.
For this elements are also attributes set in the g3.gui.res file, and may changed on the same way, but that's much work, and without fixing the stretched text it would look really worse.
You can DL it here:
http://rapidshare.com/files/152186560/g3.gui.3840x1024.rar.html
You have to extract it into your gothic3 folder.
should look this:
../Gothic 3/Data/gui/resources/g3.gui.res
if you want to uninstall it, delete the g3.gui.res file, or replace it with g3.gui.res.bak
Only tested on german edition v1.12 CP 1.6