Seems like I should have been able to do the original extrusion up to the surface in the first place, sometimes I suspect tangency with the extrude plane so I offset a surface like .125 to make sure of it and it still does not work.

I use the same profile and extrude past the surface and the and then do cut body with surface it works like a champ

screen shots coming up

is this an error or some sort of limitation built into the SW breps ?