Physx Objects

I have some questions regarding Physx objects.

I have a box model with a collision node. I set up the box with this datablock :

datablock PhysicsShapeData(Box1)
{
category = "Physics";
shapeName = "art/shapes/cube/cube.dts";
emap = 1;
mass = 5;
massCenter = "0 0 0"; // Center of mass for rigid body
massBox = "0 0 0"; // Size of box used for moment of inertia,
invulnerable = true;

};

I then use box.applyimpulse(box.getposition(),"10 0 0")

to try and move the box in the positive X direction. The problem is that the box also rotates some small amount and results in a slightly different direction than intended.

I also want the box to have zero friction, is this possible? I took out all elements of the data block that would seem to indicate drag or friction but the box still stop at some point.