How to model to avoid orientation problems

I have a simple tank model,

but for some reason, when it is imported and I place it on the ground of my level. The X and Y are rotated by -90 (or + 270) degrees. This prevents it from aiming correctly at the player when I apply a lookAt script to it.

here is the script

    var myTransform : Transform;

function Update () {
transform.LookAt(myTransform);
transform.rotation.z = 0;
transform.rotation.x = 0;
}

However in MAX, my pivot points are OK. And the script works OK as well. I am positive that this is caused by the model, because I have applied the same script to a cube with a rectangle parented to it, and it behaves as it is supposed to.

What is it that I have done wrong with the modeling ? Any idea ?

possibly when making the model you had it turned on the wrong axis.... you could just go back and rote it 90 degrees and everything should be fine :D have a merry christmas

Edit:

Or rotate it the correct way in unity3d and than place it in an empty game object... attaching all scripts to the empty game object instead of the model...