Problem with lyrics (or should I say without lyrics?)

[Dominic Sacré]

Hi,

Some parts of the score I'm currently working on (my first one with lily :) 
contain lyrics, some others don't.  Now my problem is that, even if a part 
doesn't contain lyrics, lilypond increases the distance between the staffs as 
if there were lyrics between them.

Here's a simple example:
The 2nd an 4th grand staffs are ok, but the 1st, 3rd and 5th aren't...
And if I use "\translator { \HaraKiriStaffContext }" the empty parts of the 
upper staff are removed, but the space for the lyrics is still there...

What can I do?

Thanx,
      Dominic

-----------------------------------------------
stupid_melody1 = \notes \transpose c'' { c4 d e f g a b c' }
stupid_melody2 = \notes \transpose c'' { c2 d e f }
stupid_lyrics = \lyrics { do re mi fa so la ti do }

\score
{
  \context GrandStaff
  <
    \context Staff = one
    {
      \addlyrics
      {
        \notes { R1*2 }
        \stupid_melody1
        \notes { R1*2 }
        \stupid_melody1
        \notes { R1*2 }
      }
      \context Lyrics
      {
        <
          \stupid_lyrics
          \stupid_lyrics
          \stupid_lyrics
        >
        <
          \stupid_lyrics
          \stupid_lyrics
          \stupid_lyrics
        >
      }
    }

    \context Staff = two
    {
      \stupid_melody2 \break
      \stupid_melody2 \break
      \stupid_melody2 \break
      \stupid_melody2 \break
      \stupid_melody2
    }
  >
  
  \paper
  {
%    \translator { \HaraKiriStaffContext }
  }
}