Sideeffect of avoiding grace note bug (lily 1.7.13)

[Alexandre Beneteau]

Hello,

Needing to avoid grace note bug mentionned in the documentation 
(http://lilypond.org/development/Documentation/user/out-www/lilypond/Grace-notes.html#Grace%20notes),
I use \grace {s8} getting the sideeffects you can see (little snippet 
and png attached)... (bar 3 in the upper Staff is empty when 'R' is 
requested=

You may know the problem, so excuse this message if you already do...

(This is a real problem, since it occurs in *real* music :-)) 
(Orchestration of Debussy's "Poissons d'or")

Thanks,

        Alex.

\include "italiano.ly"

\header { tagline = "" }

\score {
  \notes \relative do' {
    \context StaffGroup=bois <
    \context Staff = hautbois {
    \time 3/4 R2.*2 \time 2/4 \grace {s8} R2*2
    }
    \context Staff = clarinette {
    \time 3/4 R2.*2 \time 2/4 \grace {do8} do4 do do2
    }
    >
  }
}