Can't use optics properly on custom weapon

[citatusnimtotren 10]

Hey ,
 
I'm having a bit of trouble with optics on my gun. When attached, the model of the optics appears to attache to the weapon properly. However, when aiming down the sights, the character looks along the gun, preventing proper aiming. When a scope is attached, the view turns 90 degrees clockwise, facing the user's right side.
The model was imported to a .p3d using Arma Toolbox for Blender. The proxies for the weapon have been tested both as is (from Blender) and from O2 with identical results.
What am I missing?

.p3d (Dropbox)