I don't think MenuBar skinning is fully functional in non-per pixel skins, either - the item button graphic is no longer getting used in the MenuBar in OE6, for one thing. Some apps are getting the bar fully skinned, though.
Does WB do something "different" based on the presence of per pixel images? Is there a separate flag somewhere that tells WB "This is a WB5 skin, not WB4"?
Is MenuBar skinning history or will WB5 get that back with a future release? It's not particularly pretty the way it is. I'd trade the per pixel borders for the MenuBar, myself, if that is the choice to be made.
Cheers,
Daiwa