Sunroof won't close all the way

Need your help. I am trying to fix a friend's sunroof on her '99 Alero and it will not close all the way. I checked the track and it is well lubed but I can't seem to find what is causing it to stop. It opens but when I try to close it, it stops about 6" too soon. Any idea where I need to check? Thanks.:banghead::banghead::banghead:

pretty sure the rook moves by way of a cable,
that a motor winds onto a spool/pully.

Could hav troubles in that area, you sure thiers nothing in the back of the track, or the front, keeping it from going down and closed?