I brought in my new guitar, slighty worried that I bought the ultimate clunker. I couldn't get rid of the buzz, especially on the higher frets of the D string. The tech took it in and adjusted the action on the truss rod, which only made it less playable, so I took it back again, and showed him how you have to hold the guitar just right to hear it really buzz.
Was it a broken brace? or a loose wire? - God forbid, split wood?
Nope, just a loose security tag taped to the inside of the body!
Now it's as sweet as can be!:)