Changing polyphonic per-voice rest position

[Bruce Bertrand]

Hi all,
I'm new to Lilypond and this list, so please forgive me if this has already been
covered.

I'm trying to change the vertical position of rests in a polyphonic staff.
I found this thread:
http://lists.gnu.org/archive/html/lilypond-user/2006-01/msg00005.html

which says to use " \override Rest #'staff-position = #x " with in the voice
context.  That works quite well when using a non-zero number.  But I want to
make the rests for voiceTwo appear centered on the middle line, and using "0"
does not move the rest at all (ie. it appears where a voiceTwo rest would
normally appear).

Is there something I'm missing?
Here's an excerpt:
--------------------------------------
\version "2.8.0"
rh = \relative c'' {
        c4 b8 a g f e d| c4 e8 g c4 r|
}
                        
lh = \relative c {
        <<
        \context Voice = "1" { 
                \voiceOne 
                e8 g e g  d a d b| c e g c  c,4 s|
        } \\
        \context Voice = "2" { 
                \voiceTwo
                \override Rest #'staff-position = #0
                c2 f,4 g| c,2. r4|
        }
        >>
}

\score {
        \new PianoStaff <<
                \set PianoStaff.instrument = #"Piano  "
                \new Staff = "upper" \rh
                \new Staff = "lower" {\clef bass \lh}
        >>
}
--------------------------------------

Also, I tried subscribing to the list through the form at
http://lists.gnu.org/mailman/listinfo/lilypond-user , 
but I never got the confirmation email.  Do I automatically get subscribed by
sending this message from
http://post.gmane.org/post.php?group=gmane.comp.gnu.lilypond.general ? (I
suppose I'll find out soon)

Thanks.
Bruce