Problem of chords with lilypond 2.10.33 under debian lenny

[Le Piaf]

Hello everybody !

I just discover lilypond and want to make, in one page, a list of some 
chords with their names above.
In order to do so, I tried to use \chordnames.
I got two problems :

First, not all the alterations are visible before each chord, because 
lilypond considers that some alterations have been showed before.

I tried #(set-accidental-style 'forget) but it seems to have strange 
behaviour (second and "invisible" staff above the one where the chords 
are, but a key is showed)...

Secondly, I want to have one "type" of chord on each mesure. For 
example, every "c" (major, 6, 7, minor, and diminued) in the same mesure.
Then, every "des", etc.
What kind of \time command should I use ?
Is there another (and simple) way to do that ?

Could you help me to do that ?

I hope you'll understand my english.
Please answer in very simple words, or in french if you can (in private 
then)

I join a example of my try : the ".ly" file.

Thanks !

Le Piaf

*********************** .LY FILE *************************************
% Accords
\version "2.10.33"
\header { title = "Accords" }

accords =
{
  \chordmode
  {
     c2:maj7    c:6    c:7    c:m7    c:dim    \break
     cis:maj7   cis:6  cis:7  cis:m7  cis:dim  \break
     des:maj7   des:6  des:7  des:m7  des:dim  \break
     d:maj7     d:6    d:7    d:m7    d:dim    \break
     dis:maj7   dis:6  dis:7  dis:m7  dis:dim  \break
     ees:maj7   ees:6  ees:7  ees:m7  ees:dim  \break
     e:maj7     e:6    e:7    e:m7    e:dim    \break
     f:maj7     f:6    f:7    f:m7    f:dim    \break
     fis:maj7   fis:6  fis:7  fis:m7  fis:dim  \break
     ges:maj7   ges:6  ges:7  ges:m7  ges:dim  \break
     g:maj7     g:6    g:7    g:m7    g:dim    \break
     gis:maj7   gis:6  gis:7  gis:m7  gis:dim  \break
     aes:maj7   aes:6  aes:7  aes:m7  aes:dim  \break
     a:maj7     a:6    a:7    a:m7    a:dim    \break
     bes:maj7   bes:6  bes:7  bes:m7  bes:dim  \break
     b:maj7     b:6    b:7    b:m7    b:dim    \break
  } % chordmode
} % accords

\score
{
  <<
    \new ChordNames \accords
    \new Staff \accords
  >>

  \layout{}

} %score

*********************** END .LY FILE *********************************