Facial Rigging smooth bind playing up.

[morgjon]

Hi, im having a bit of trouble with the facial rigging kit. its a great kit and really enjoying it but im having a bit of trouble with the bind. it is all working great and got all the controls for the jaw and eyes working. and am now up to doing all of the different poses for the mouth. but... while i am doing the poses. and i go back to play with the mouth controls on the original face they have lost their bind on the actual face. Everything else is binded correctly (the eyes, eyebrows, toungue...etc.) but the actual face doesn't move. its really weird because i go back to one of my previous saves. and import all my poses that i have been working on and it will work again for a while. and one or two poses that iv done later.. the face controls don't move the face. its not a big deal to fix up. but its just really weird and somewhat annoying...
so if anyone could make sense of that...any ideas what could be causing it or any suggestions?
im using Maya 8 on windows XP

cheers