Howdy ppl. I got a small problem with my fernandes (fender wannabe) I tune the strings correctly and all open strings is perfect tuned. Its perfectly tuned at 12th fret but when I do a F(1stfret) its suddlenly mistuned, same goes with F# and G. on E string that is . When I get to 4th fret it is suddenly good again. Any ideas what to do?