I have a ibanez SA260fm and i noticed that on the end of each sadle there is a threaded hole. in five of those holes there is a threaded sort of pin, should there be a sixth pin for the 2nd string because there is no pin in its hole? are these needed for any reason? ive had the guitar for 2 weeks and its working fine and i have only just noticed the missing pin and have looked everywhere around my house and havent found 1..... can any1 help?