Problem with alignment of Chord Symbols over notes.

[Richard Shann]

Can anyone spot the error in this:
8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
\version "2.19.25"

\score {
          <<
             \new ChordNames \chordmode {  e4 s4 f:/g8 s8 s4 
                                           d8:m s8 s8 s8 s8 s8 s8 s8  }
             \new Staff {
                         d'4 d' b8 d' f4
                         a'8 g' a' g' a' g' a' g' }
          >>
       } 
8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
run under Frescobaldi (which says version 2.18.2) it gives
warning: Spurious garbage following chord: (#<Pitch c'' >)
and the Dm chord symbol is shifted to the right - without the /g the
positioning is correct.

Richard