Moving rests vertically in drummode

[Nicolas JOYARD]

Hi all !
I just discovered Lilypond and started writing a few scores. But I have a little
problem. I'm writing two-voiced drum scores (one for cymbals, the other for
drums) but when I write something like :
 --
  { \times 2/3 { hh16 r hh } } \\
  { bd8 }
 --
the rests in the first voice get centered on the staff... And I can't move them
by using the <note>\rest trick because notes aren't defined in drum mode (I
tried hh\rest but it doesn't work as well). I would like to have the rests at
the same height as hh notes, as it happens when the second voice has notes
simultaneous to the rests like in the following :
 --
  { \times 2/3 { hh16 r hh } } \\
  { \times 2/3 { r bd r } }
 --
in this second example, every rest is aligned along with it's voice's notes...

Do you know a way to do that ? I didn't read the whole doc, but I searched a lot
and didn't find anything...

Thanks !

(ps: i replaced >>'s and <<'s by -- because my client then accused me of
top-posting...)

Nicolas