generating a one-and-a-half story house?

[ptmurphy]

I am creating a one-and-a-half story house with a common back roof plane, but separate front roof planes. I used the method shown in the training video:

1) Create a second story based on first story
2) Set the gable walls on second story
3) Set the ceiling height (0-1" in my case) to set the second story wall height.
4) Build automatic roof planes (10/12 in my case)

(No artifact at this point)

5) Reset the ceiling height to the desired (90" for me) and rebuild walls/floors/celings.

After step 5) a wall segment is extented from the lower roof plane to the upper. See attached picture (forward roof surfaces deleted). Can't get rid of it no matter what I try. TIA.

Using Pro 6.04.

ptm