yeah i also agree,,,,the probable cause is the nut, but good tuners make a huge dif too, but i'd take joes advice and try the oil,,,,,one thing gibson might have been screwing up on all these years (dare i say gibson screws up) is the slot width of the nut, or it just could be the design of the headstock and which way the string gets pulled to the tuner,,,,a good guitar will always stay in tune if the slots in the nut are CLEAN,,if they are dirty or not sized right, when u bend a string or get aggressive in your playing, the string could be binding up in the slot, imagine the slot being all cruded up or too small so the string can't slide freely, when u bend u pull the string into the fretboard, then when u release, the string doesn't slide back towards the tuners, that is why joe recommended the bore oil, it could ust do the very trick, or a good tech (like joe was saying) could just file that slot the perfect width for u,,,,,unless u feel comfortable doing it youreslf of course.....then u can (if u want) upgrade in better tuners once you are sure the slot for the g string is right (heck, might already be, maybe it is the tuners, but i doubt it, i've used crapy $29. can. tuners and they work fine if the nut is working properly,,,,oh yeah, like someone was saying up there, a thicker gauge string would really help too, but u are using 10's so u should be fine (if it's an electric, u are fine, if not, go to 12's er 13's) good luck.