Tryed to follow your workaround.

Under the steam installation folder there is no profiles directory.

Checked the usual suspects out and found the sneaky bugger hiding at :-
C:\Users\username\Documents\Larian Studios\Divinity Original Sin

there is a profile dir there, no actual .xml files but .lsx (in xml format)

inputBinding.lsx the only semi related file I could find however it only contains keyboard bindings and none for mouse.

EDIT:- I have a steam version.

Last edited by Salahn; 01/08/14 02:03 PM. Reason: additional info