Mysterious octave shift

[Rene Tschirley]

Dear lilypond experts,


I'm very sorry to bother you, but even after carefully reading the
documentation and some of the list's archives, I still have no clue.

During my very first steps using lilypond for my personal collection of
songs, I found some odd behaviour. 

I'm using embedded lilypond notation and tried this:

\begin{lilypond}
  \score {
    \notes { 
      \relative c'{ 
        \key d \minor
        d8 d e f a d d d
        d d e f a bes bes bes
      }
    }
  }
\end{lilypond}

I was very surprised to see the notes of the second measure one octave
higher than expected ('' instead of '). The behaviour may be suppressed
by changing the notes to

        d8 d e f a d=' d d
        d d e f a bes bes bes

but that's not what I'm supposed to do, isn't ist? I noticed that the
octave shift occurs, whenever the stem of the second 8th group changes
the direction and goes down. If I use these notes:

        d8 d e f g d d d
        d d e f a bes bes bes

everything is as expected.

Can anybody explain me, what happens here? Is this a bug? A feature? A
user-too-dumb error?


Yours,
René


-- 
René Tschirley, PhD
http://www.tschirley.com