Hi, techies -- I have acquired a small Martin travelling guitar, and I notice that as soon as one puts a capo on the higher frets, say above 3, the guitar goes out of tune, and has to be retuned. On a standard one has usually to retune a bit, but not this much. I know nothing about the physics of this -- a small guitar has the same size strings, just a smaller body. Or is there something wrong with the guitar: it seems as if the bass strings go out (sharp) the most.

Any wise words appreciated before I go to the trouble of taking it into a shop somewhere.

yours,

Peter T.