Try setting just one folder to sharing and see what happens. I have had the same problem and this seems to have taken care of it for me. When I set a drive to share it does not share all the folders in that drive just the root of the drive. Try copying something to the root of the drive and see what happens.

I have read many a post on this topic and it seems that some will work by just setting the root of a drive to share and some you have to set the folders to share............... Go figure....