More info, thumbnails
Well, I published the pages to a live server and I don't see the slice that is visible in DW in the design view. I'll post some thumbnails here.
I'm beginning to think it's a feature in DW, something set to visible, perhaps?
EDIT:
Ok, in DW, checking live view makes the black stripe go away. Under View, Visual Aids, Invisible Elements, unchecking this item makes the "stripe" go away. I'm guessing this is a headspace and timing issue.