Trouble With Managing Walls, Invisible Walls And Columns

[4hotshoez]

At one juncture in my plan I have a 12x12 column with in an invisible wall and an interior wall. The invisible wall wants to react with the visible wall will do strange cuts to the wall so I had to spend much time tweaking the layout for these items to coexist peaceably 

 

Another location on the plan I have an room divider with no thickness and as soon as I draw it, it becomes thick like a regular wall with materials, but invisible. Maybe I don't need it, but it is a porch with a roof. In some other places I did not have trouble with the wall adopting a thickness. So I drew the single lined room divider away from the location and then moved it in, but it became thick again. Is this a bug? 

 

Attached files:

[Joe_Carrick]

These things are tricky.  Most likely the "Thicker Wall" is a result of having a Floor or Ceiling Height difference - but it could be something else.