using run-translator

[Jan-Peter Voigt]

Hi list,

I am using `ly:run-translator` to analyze a music expression.
If I use << \\ >> simultaneous expressions with voice separator and set 
a key signature at the start of the expression, no voice separation is 
done and lily gives a bunch of warnings about colliing notes:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% voicify does not work in ly:run-translator, when a keysignature is given
%mymusic = \new Staff { \time 3/4 \key f \major \relative << { bes'4 } 
\\ { g8 f } >> }
%mymusic = \new Staff { \key f \major \relative << { bes'4 } \\ { g8 f } 
>> }
% this works without a problem
mymusic = \new Staff { \time 3/4 \relative << { bes'4 } \\ { g8 f } >> }
mylayout = \layout {}

#(ly:run-translator mymusic mylayout)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Do I have to consist some special engraver to the layout used in 
run-translator? Or do I have to look for something else?

TIA
Jan-Peter