Additional spaces for \rest ?

[Thomas Scharkowski]

Hello,

the following example produces rests (\rest) which are placed some 
spaces over or under the desired position in upper or lower voice 
respectively. It did not happen in previous versions (around 2.0.1).
Is this a bug?

Thomas
cygwin
xp

--

\version "2.1.25"
\score {
\notes {
%Oberstimme
<<        {
        \relative c''{
        c4 c r c
        c c c\rest c
        }
        }
%Unterstimme
\\      {
        \relative c'{
        c4 r c c
        c c\rest c c
        }
        }
>>
 }

\paper {
raggedright=##t
\translator {
\ScoreContext
\remove Bar_number_engraver
}
}
}