especially if you have embedded guitar chords.

I suspect that will be due to different abcm2ps versions in use. folkinfo is usually within one or two releases of the current stable version and is up to date at the moment.

I'm actually using 2 versions of abcm2ps at the moment as I've added experimental support for the svg (scalable vector graphics) format which only exists in the development version. I'm not sure what other features the development versions may add but there is a chance that the svg link will (for better or for worse) produce different output on the score to the png/pdf.