Suddenly no \break (lilypond-book)

[Wolfgang Mechsner]

Hi,

suddenly, the \break doesn't work with lilypond-book (version 2.6.3): 
Any idea?
Wolfgang

#####################
\begin[staffsize=26]{lilypond}
emptymusic = {
       \repeat unfold 2 % Change this for more lines.
       { s1 \break } 
       \bar "|."
     }
     \new Score \with {
       \override TimeSignature #'transparent = ##t
       defaultBarType = #""
       \remove Bar_number_engraver
     } 
<<
       \context Staff \emptymusic
     >>
\end{lilypond}
####################

Wolfgang Mechsner
Goebenstr. 3
49076 Osnabrück
Tel. 0541-2052090
Mobil 0179-9096684
address@hidden
www.wolfgang-mechsner.de