I seem to have a problem making these snap right, they seem to only attach to the bottom of walls, and not to top so I can't seem to make it connect to a wall so it can make a roof properly. Maybe this was broke in a recent patch?

https://dl.dropboxusercontent.com/u/364541/RoofAttachments.jpg

You can see above where it wants to attach to the bottom of the wall no matter how hard I try to get it to attach to the top of the wall.