Teeth don't follow jaw bone properly?

I was using a simple jaw bone to see how my model would look with mouth movements.

Weight painted the jaw mesh to the bone just fine. Parented the teeth object to the bone.

The teeth follow the bone but not completely accurately. they slip forward in y when the jaw rotates along x. What would be the first things I should look at when having this problem?

EDIT: re-created bones, seems fine now.

Hm, i am not sure, but maby teeth have been perented to few bones. Is teeth separete object?

Well I just deleted the bones and did it again and it seems fine now. I must of had a weird scale problem or something with the original bones. Just needed it so I could work on getting the teeth positioned good. Mouths are a pain!