voice follower broken?

[Atte André Jensen]

The following reduction shows some stange behaviour with
PianoStaff.followVoice. It seems that tuplets break the followers, since
uncommenting the lines containing quarter notes displays the lines just
fine. It this a bug, or am I doing something wrong here? And is there a
way arount this. I'm using 1.6.9...

-- begin lily --
RHa = \notes  \relative c' \context Voice = RHa {
% the following line won't work...
    | \times 4/6 {a''16 e a, e' a, e } \times 4/6 {e' a, e a e a, }
% the following line does work...
%    | a4 a
    \translator Staff=down 
    a,4
    \translator Staff=up
    <a'''\arpeggio  c e a>
    | s1
}

LHa = \notes  \relative c \context Voice = LHa {
% the following line won't work...
    | \times 2/3 {c8 a' e'} \times 2/3 {e, c' a'}
% the following line does work...
%    | a''4  a
    \translator Staff=up <c4 a'>
    \translator Staff=down s4
    | a,1
}

\score {
    \context PianoStaff
    \notes <
        \property PianoStaff.followVoice = ##t
        \context Staff = up <
            \clef treble
            \RHa
        >
        \context Staff = down <
            \clef bass
            \LHa
        >
    >
}
-- end lily --

-- 
peace, love & harmony
Atte