Originally Posted by danutz_plusplus 
It's just for certain cinematics. For the example the first one after escaping from the prison, before getting to Flotsam. The one narated by Dandelion.
This one: http://www.youtube.com/watch?v=raT_1gbWeng
Did it work for you with 16:10? On mine and other people's 16:10 resolutions it didn't.
I see, not checked EE exclusive cinematic yet. I remember The Witcher used to have problems with blocky cinematics at 16:10 so perhaps they've got something odd with their sizer.