Seaking

I have this problem with my Suzuki 3S which is basically a Martin copy. Have spoke to some people about it and it is likely due to the string gauge used and the placing of the capo. I have extra Elixir extra lights fitted and like you often play in an alternate tuning (DADF#AD).

It is quite likely that it happens because the action of my guitar has not been adjusted for the open tuning but left as it was for tuning in concert. However that said I play in both and occasionally dropped D so I just put up with it and re tune the offending 2nd and 6th strings. It also seems to help if you position the capo close to the fret.

I like you would appreciate any further enlightenment!

Chris