I just bought a brand new Yamaha apx500ii and found some fret buzz when i got home.

the low E buzzing after the 12th fret then stops at fret 16.
the A string starts buzzing at fret 8 and then stops at 11.
the D string starts buzzing at fret 3 and stops at 7.
the G string buzzing open and stops at 4.
the B string only buzzing at the first fret.
and i Cant hear any buzzing on the high E string
Sounds like some uneven fretwork..take a short strait edeg (3 frets long) and see if it rocks at any point along the fretboard as you bridge 3 frets at a time. If it does then the frets are either not seated properly or in need of dressing.