Purchased a Pro Stringer (portable one). I've never used floating clamps before, as 90% of the racquets I've strung were on a Babs Star 5. Right now everytime I lock the floating clamp on the two middle, then go to the next hole and pull tension to start the mains the string snaps or slips out of the floating clamp everytime. Beyond frustrating now. Am I doing something incorrect? Went on YouTube and watched the vids and am doing exactly what these guys are doing. It is rough poly (Babolat RPM). But still.