Hello,
You've got to go to "sharing options".
You should disable the folders mirroring, I mean "desktop", "documents", etc... by unflagging the default list you see in the lower part of the sharing options menu.
Instead, you should manually list the folders you wish to share by clicking on "+" button and selecting the folders one by one.
Try it, Win8 should refresh the desktop and automatically connect the shared folder network unit.
Hope I was clear enough,
Ciao