Unnecessary columns in auto-created Design Tables

After I've created a couple of configs in a part, I'll usually auto-create a DT.  When I look at it, I find that SW has added several unnecessary colums (eg "TOLERANCE@d1@SKETCH1") and placed "NONE" in every row beneath it. It happens a lot and I can't work out why it's doing it. I don't want these tolerances appearing in my DT unless I ask for them! It seems like a completely random thing; not every dim is affected. (Is there a secret secret radio button hidden somewhere - "Cheese off User" ?) Anybody any ideas?

SolidworksConfigurations design Tables