Collision box trouble

I'm working on a door for a prison cell. These are the old fashioned prison doors too, like this:
http://onlinegreensboro.com/~lwv/GCcell15.jpg

I'm having trouble setting up the collision boxes for this. I put boxes around the individual poles, and it stops the player model from walking through it, but it is also stopping the bullets. I want it so that you can shoot between the poles.

I'm using 3ds Max 2011. I have the boxes named as col-X and have them linked to the door, which is linked to start01. I have dummy objects named collision-X and have them linked to base01.

Is there a minimum size that collision boxes need to work? The collision boxes for the poles on the door are .05 x .05 x 3.

We are using TGE 1.5.2.

Thanks,
Krogoth