I changed out my strings on my Peavey Wolfgang this weekend and now I'm having issues with it staying in tune. The locking nut screws are as tight as I can getting them but when I slightly use the whammy bar, it goes out of tune. I did notice if I pull up on the whammy it raises in pitch and it's not a floating trem. I dont want to block it because I like using the whammy. My first thought was strings slipping in the nut but it is tight. Maybe the springs are worn out? Anybody got any ideas?