Just found this thread and have to give a big thanks to Chrisay for the write up. I was having the same problem with the rear door in my '08 outback, and decided to dismantle today.
Apparently I had the opposite problem to everyone else; not a drop of grease to be found in the assembly. Motor was completely seized. I don't think the ebay replacement will save me here
http://i.imgur.com/Pu8aR.jpg
http://i.imgur.com/TOlYj.jpg