Today SW has decided that when asking to view a section cut in my assembly it will section everything ... except the one component it has decided it will no longer section.  As usual, it "used" to work, but today it won't.  The component has been part of the assembly for months so it isn't something just added or changed.  When it draws the preview before clicking OK on the section box it show it sectioned.

Any ideas why it doesn't want to work today or how to find out what it thinks it is doing?