The safety on my PS90 would squeak when it was moved from S to 1, and it was seriously irritating me. So today I took the stock apart, which was a little difficult but not bad, and put a little Armour All on the little plastic tabs that hold the selector in position. All better!! I now can move the safety without hearing the little squeak and its a lot smoother since the treatment. If anyone else is having this problem I strongly suggest doing this as it will easily and quickly solve the problem. :?