[Zbrush] Weird problem, polyframe showing on surface of model

Hey, this is more of a query and if this has happened to anyone else... Ive got sub divs on my model and if I move from a lower to a higher level between sculpting, the poly wire frame shows up on the surface of my model (pic 1).  Its weird, I can smooth it out and it disappears but when I drop back down a few levels and then move up to the highest sub level, it shows up again... Anyone had this problem before or know how to fix it?