I got a Martin DCX1E this Christmas and today I noticed that the 13th fret of the e string was flat. I figured it must be the strings, so I changed em, but the note is still flat.

Does anyone know why this might be happening?
possibly your neck is warped in such a way that it causes this? maybe there is someting in the peg hole on the bridge casuing this?

Ibanez RG7621
Ibanez RG121
It's too complicated.

If intonation is the problem, I'm going to have to take it somewhere to get it fixed.
Yeah it's the intonation and that most likely means that it will require some adjustment of the saddle which on an acoustic is best left to a pro. IMO you should just bring it to a good luthier for a regular set up.
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