Strange behavior with piano sustain in midi output

[Michael Pozhidaev]

Hello!

Yesterday I have noticed some strange behavior with 
using sustain pedal marks in midi output during the writing piano piece score.
I have removed some code and left just the minimal 
snippet, where this problem appear.

I am not sure, but it seems to me in old lilypond 2.11.0 everything was OK.
In the listing below there are two marks.
In the line under the %%mark1 sustain commands do everything correct,
but in the line under %%mark2 output sounds as there is no sustain.

I have performed some experiments and noticed that this problem disappear 
if  remove \key command. But in large score this removing 
does not make same effect.

Please, say, what is it? Is it a bug? Can I fix this? Currently I am using 
lilypond 2.11.61.
The midi fragment I got with this listing is placed at
ftp://ftp.altlinux.org/pub/people/msp/tmp/fragment.midi
Thanks!

\version "2.11.61"

partOneLeft = {
  \key c \minor
  \time 6/8
  \clef bass

  \tempo 4 = 140

  \partial 4  r4
  es4( g8 <bes es'>4 g8
  <bes es'>4 g2)
  <f as c'>4. f'4( c'8
  f4 as2)
  <g b d'>4. g'4( d'8
  g4 b2)
  c4( es8 g4 c'8
  c2.)
  as4( c'8 <es' as'>4 c'8
  <es' as'>4 c'2)
  f4.( <as c'>4.)
  f4.( <as c'>4.)
  g4.( <b d'>4.)
  g4.( <b d'>4.)
  c4( es8 g4 c'8
  c2)
}

partOneLeftMidi = {
  s4
  s4 \pppp \sustainOn s8 s4 s8
  s4 s2

%%mark1:
  s4. \sustainOff \sustainOn s4 s8
  s4 s2 

%%mark2:
  s4. \sustainOff \sustainOn s4 s8
  s4 s2
  s4 \sustainOff \sustainOn s8 s4 s8
  s2.
  s4 \sustainOff \sustainOn s8 s4 s8
  s4 s2 
  s4. \sustainOff \sustainOn s4.
  s4. s4.
  s4. \sustainOff \sustainOn s4.
  s4. s4.
  s4 s8 s4 s8
  s2 \sustainOff 
}

\score {
  \new PianoStaff <<
    \set PianoStaff.instrumentName = "piano"
    \new Staff = "lower" << 
      {
        \partOneLeft 
      }
      {
        \partOneLeftMidi 
      }
    >>
  >>
  \midi { }
}
-- 
Michael Pozhidaev. E-mail: address@hidden
Tomsk State University. http://www.csd.tsu.ru
ALT Linux Team. http://www.altlinux.ru