This is just a guess, but it might help you anyway:
E.g. A manually operable clamp for removing the sprocket feed margin strips from continuous computer print-out paper when the strips are removably attached along...: http://www.freepatentsonline.com/5007571.html

Or: "The only way around it seems to be to waste paper by increasing the feed margin for every print. Has anyone found a solution?": http://forums13.itrc.hp.com/service/forums/bizsupport/questi...