Thank you for the suggestions, but I'm sorry to say these do not work. Of course, not mulling them is an easy solution, but not the right solution. There is a reason I want them mulled. Not mulling them has its own problems. It's technically a door and being treated as such so the casing should not be wrapping around the bottom of the doorway. The window attributes seem to be overriding the door settings. I guess I'll be "patching" the sill area with a P-Line Solid or maybe trying the floor material region to fill in the floor. Thank you again for the suggestions.