Originally Posted by Burning Down

Well I'm guess that since you had the truss rod adjusted, it could be one or two frets that need to be filed down a little bit. My friend had the buzzing problem with her classical guitar - she had the truss rod adjusted and there was no warping, but the guy at the shop said that there was a fret that was a little higher than the rest. He filed it to be even with the other frets and she hasn't had a problem since then.