eye rigging problem

I have a problem with the armature in a model I am working on. I have the face rigged up, and I am trying to make it so that the eyes will rotate to follow a lookat bone. However, when the eye bones rotate, they will only rotate around the global axis, rather than the local axes for the eyes, so that the eyes actually rotate out of their sockets. Has anyone else come across this problem, or a way to fix it? Thanks.

I usually make my eyes seperate objects parented to the head bone. Then just a simple track to constraint towards the eye target.

I made an example blend in this thread:

did you check the CGcookie video tut on face