http://www.youtube.com/watch?v=13_ksmGcuuo

Strange problem. Seems to open happen when going up. Going down is fine?
I've lubricated all the runners and its still happening.
Seems to be coming from the center runner though. I can't figure it out...help!

 

Perhaps its something in the motor

 

not too sure about that. it really sounds like rubber against glass? i cant pinpoint where it is though. and i've silicone sprayed all the runners