\slurUp and \slurDown don't work any more with lilypond 1.3.11{5,6}

[Alexandre et/ou Sophie Beneteau]

I' ve typeset this test.ly :

\header {
    tagline ="";
}
\include "italiano.ly";
\score {
    \notes
    \relative do' {
    \time 4/4;
    \partial 2;
        \slurUp
        do2 ~ do do' ~ do
        si ~ si do
        \bar "||";
        \break
        \slurDown
        r2
        do,2 ~ do do' ~ do
        si ~ si do
        \bar "|.";

    }
}

[see test.png for the result]

It seems that \slur{Up,Down} don't work...

[It should not be a problem, because I think the user has not to
determine the slur direction : music should be the only thing he has to
descripbe and NOT the typography ; but since lilypond can't find yet the
best solution in very hard cases (I should not blame it, I guess the
problem is really hard to solve :-) ), like in fugas with 3 or 4 voices,
the user has to help it with this sort of instructions...]

Anyway thanks a lot for such a good and userfull software :-)

        Alex.