I've had an Ibanez GRG250DX for the past week and so far its been great, just one problem recently. I tried tuning it into a lower tuning(C# G# C# F# A# D#) by loosening the nut and then tightening it when it was tuned, but it kept going back into standard tuning and i was really annoyed so I put it back into standard and it keeps going out of tune by 1/4 of a step and im really annoyed! Anybody know how to help???