yeah, depending on where it is it's either a screw screwed in too far, or an edge dent that pushes it in. There's really nothing you personally can do (I'm assuming your not a shop tech since your asking), but DON'T sand the base, you will end up very unhappy. Take it to the shop you got it mounted at and show the shop tech (not the guy behind the counter - unless he is the tech - ask to talk directly to the actual tech - they'll either fix it, or (if it's their fault) they should compensate you in some way (I'm not saying new skis, although they might, but don't go in there demanding new skis, cause that most likely wont work).