does any1 know a 100% working solultion for this problem?
I've somehow managed to fix it on one unit. and then made another 2 with dual barrel (the posted gatt and an overlord re-model) and the bug just came back on all of them o.O
I know it's the model, since e.g. original overlord works well with the code, while my model doesn't.
Can some1 please sub the attached models for their overlord and see if they get the same bug (i.e the unit aims slightly off the target, see SS)
    Dictator.rar (38kb) downloaded 1 time(s).

Problem narrowed down to turret, if I switch Overlord's turret with mine (on overlord's code), the overlord will aim like a retard - see attachments, blue line shows how it aims, while green one how it should - you can see he's using barrels' pivots (local axis) as aiming reference rather than turret's one, wtf?
On the other hand, if I use overlord's turret with my hull and code, everything is fine.
P.S does any1 know what 'FLAG' bone is responsible for? look @ the last image, it's in a weird position, and nothing is attached to it in-game.

Well, it looks like if you have a unit with more than one barrel, and it's size is overlord-like.
the unit must have both, the chassis and turret centered at 0,0, if not, the aiming bug will appear and it will hurt your eyes every time the unit has to turn its turret more than 10 degrees.
P.S can any1 confirm same bug on quad cannon when you look up closely? i.e if unit aims at target ~90 degrees from its natural turret orientation it aims with one of the barrels instead of the middle of the turret?