To Alpha:
You're a legend bro. Been struggling with this for hours. Finally working now thanks to you and your 5 year old post.
For others still having trouble:
1. Select Shell of the object causing issues (Will say "Shell" in it's name)
2. Select Parameters tab.
3. Use "Shell" dropdown menu, then "Visibility" Dropdown menu.
4. Select Surfaces, then switch the parts you don't want the shell to cover to "Off."