OK, so as some others have noticed, the crosshair is not compensating for translations (leaning).
So for now turn OFF the X, Y and Z axes, else head movement will affect where the crosshairs fall.
You do not really need X, no big loss.
Z is also not a huge loss - you gain very little extra "zoom".
Y (head up/down) however can be useful, as shown in the pics above. Recommend setting a big deadzone on it though, so it only affects aiming when trying to look down more than you normally would.
Also, has anyone else noticed that with TrackIR, it is possible to look down your own neck? Lean back and look right down!
Oh and also I noticed that the cockpit of the stalker has some holes in it. If you look up and to the side you can see the roof is not complete.
Edited by evilC, 03 June 2014 - 04:44 PM.