Every location is different but I've always seen Tyvek on before the framing inspection. A lot framers wrap each section of wall while it is flat on the deck before they lift it up. Just make sure they can see the grade stamp on the exterior sheathing for the inspection. They'll also be interested in the nailing pattern you've used for the exterior sheathing. If you're going to proceed, definitely take photos (the more detailed the better) of what've done before the wrap goes up.
A lot will have to do with the inspector's attitude. How has he been to work with so far (guessing that you had foundation inspections prior to framing)?
