Programming error at calculating line breaks

[ludovic sardain]

Hello,

When I run the following file in Lilypond 2.6.3 on Ubuntu, I get the error 
message:

calculating line breaks...
programming error: adding reverse spring, setting to unit
continuing, cross fingers

several times, and in the output, the first notes are crossing with the time 
signature.

------------------------------------
\version "2.6.3"
#(set-global-staff-size 16)

global = {
        \key g \major
        \time 4/4
}

tenorOne = \relative c' {
        \clef "G_8"
        c4 r r r |
        R1*6
}

tenorTwo = \relative c' {
        \clef "G_8"
        c4 r r r |
        R1*6
}


basseOne = \relative c' {
        \clef bass
        c4 r r r |
        R1*6
}

basseTwo = \relative c' {
        \clef bass
        c4 r r r |
        R1*6

}

tenorSolo = \relative c' {
        \clef "G_8"
        c4 r r r |
        R1*6
}

\score {
<<
        \context Voice = tenorsolo <<
                        \global
                        \tenorSolo
                >>
        \context ChoirStaff <<
                \context Staff = haut <<
                        \context Voice = tenorun <<
                                \voiceOne
                                \tenorOne
                        >>
                        \context Voice = tenordeux <<
                                \voiceTwo
                                \tenorTwo
                        >>
                >>
                \context Staff = bas <<
                        \context Voice = basseun <<
                                \voiceOne
                                \basseOne
                                \voiceOne
                        >>
                        \context Voice = bassedeux <<
                                \voiceTwo
                                \basseTwo
                        >>
                >>
        >>
> >
}

---------------------------------------

Can you help me please?

Thank you

Ludovic SARDAIN