I'm having a problem with blendshapes for my facial expressions in Maya 4.

I've created some blendshapes and they work fine, but when I have a blendshape in use the head of my model no longer responds to the movement of the skeleton. It just stays put.

In the same way, when I pose the neck or jaw with the skeleton and then apply a blendshape the head deforms to the original pose ignoring the position of the skeleton.

I used smooth-bind for the head and rigged it before modelling the blendshapes. When I created the blendshapes I had the attributes set to default.

I've used blendshapes once before and I didn't have this problem, have I missed something in the setup of the blendshapes?

Can anyone help?

Thankyou.