I just bought a new Les paul standard pro epiphone guitar ...It sounds amazing and I love it. But I can't keep the G string in tune. I took the guitar back to the store and told the guy I wanted to exchange it with the same model. tried 3 different guitars of the same model and they all kept going out of tune. looked it up on the internet and come to find out the gibsons/lespauls are notorous for having tuning problems. what can I do to fix this problem, without having to buy a (string Butler) and yes they exist google it.