The guitar - Fender Mexican Strat (mang)
the buzz - G string at the nut

what to do????? I've tried this silicone string lubricant (careful, don't get this stuff on the fretboard!) and that hasn't fixed anything. Has anyone dealt with this and what did you do to correct it? I'd like to fix this but I'm afraid of screwing it up and making it worse.

Thanks!!!!