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?
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.