I would see if my saddle on the bridge had enough pressure on the last part before air. Then I would check the arch of the neck. Books Iv'e read tell me to put my left #1 finger on fret#1 and your right #T finger on the 15 fret. Then take the middle finger of the right hand to the 7 fret and you should have 15 thousands of a inch or 1/64 inch play between the string and the fret. Once this is cool only fret filling and or string raising is hip with respect to the lowest string action posible with out buzzin.