Bug (?) with lyrics

[Marco Caliari]

Hi all.

In the following (sorry, but I cannot reproduce in a simplier manner), I 
have problems with lyrics. 
If I comment the first lyrics, the result is good, 
even if I have several "warning: Huh? Melismatic note found to have 
associated lyrics."
The same if I comment the third lyrics.
But if I comment the second lyrics, a slur (inexistent in the code) 
magically appears in the third staff, near the end and there the lyrics
are placed wrong (also "warning: Huh? Melismatic note...")
The same if I keep all the lyrics togheter.

\include "italiano.ly"
sopranmusic = \notes \relative re' {
    \time 2/2
    \property Staff.timeSignatureFraction= #'(3 . 4)
    \property Voice.TupletBracket \set #'transparent = ##t
    \property Voice.Slur \set #'transparent = ##t
    \times 4/3{re4 re re( fa4. re8 fa8.[ sol16]) la2 la4 la4.( sol8 fa4) 
               mi( do4. la8) la4  r la' sol( mi4. fa8 sol4) do,2 sol'4 
mi4.( 
               fa8) sol2 r4 sol sol sol mi4.( re8) do4 r sol' sol sol4.( 
fa8 
               mi4 re sol4.) la8 si8.[( la16] si8 sol4 fa16 mi) re4 sol2 
               sol4 sol2( fa4 re) sol re( sol re) sol r sol( fa re) sol 
re( 
               sol) re sol( re sol) } fad1~fad}
sopranlyrics = \lyrics { A- gnus De __ i, a- gnus __ De __ i qui tol- __
                         lis qui tol- __ lis pec- ca- ta mun __ di mi- se- 
                         re- __ re no- __ bis, mi- re- re- __ re no- __ 
bis
                         mi- __ se- re- __ re no- __ bis }
tenormusic = \notes \relative la' { 
    \property Voice.Slur \set #'transparent = ##t
    \time 2/2
    la1 la la( do~do2 la do2. re4) mi1~mi mi mi(~mi2 re do1) si( sol~sol2 
mi) 
    mi1 r mi' re( si si2 do re1) sol,(~sol re'~re)\bar"|."}
tenorlyrics = \lyrics { A- gnus De- __ i, __ a- gnus __ De __ i qui tol- 
__
                        lis }
bassmusic = \notes \relative re {
    \property Voice.Slur \set #'transparent = ##t
    \time 2/2
    \clef bass
    re2 re re( fa~fa4 re fa4. sol8) la1 la2 la(~la4 sol fa2) mi( do~do4 
la) 
    la2 r la' sol( mi~mi4 fa sol2) do,1 sol'2 mi(~mi4 fa) sol2~sol r sol 
    sol sol mi(~mi4 do) do2 r sol' sol sol(~sol4 fa mi2 re sol~sol4) la 
    si4.( la8 si4 sol2 fad8 mi) re1~re}
basslyrics = \lyrics { A- gnus De- __ i, A- gnus __ De __ i qui tol- __
                       lis, qui tol- __ lis pec- ca- ta mun- __ di 
                       mi- se- re- __ re no- __ bis }
\score{
\context ChoirStaff \notes <<
              \property Score.automaticMelismata = ##t
    \context Staff = sop {s1}
    \context Lyrics = sopl {s1}
    \context Staff = ten {s1}
    \context Lyrics = tenl {s1}
    \context Staff = bas {s1}
    \context Lyrics = basl {s1}
    \addlyrics
    \context Staff = sop \sopranmusic
    \context Lyrics = sopl \sopranlyrics
    \addlyrics
    \context Staff = ten \tenormusic
    \context Lyrics = tenl \tenorlyrics
    \addlyrics
    \context Staff = bas \bassmusic
    \context Lyrics = basl \basslyrics
>>


Best reguards,
Marco