multimeasure rest bug?

[Shane Brandes]

Hello,

  I have found a peculiar thing concerning multi measure rests. In trying to use
R1 to center a full rest in a partial bar of a piece the rest disappears when R1
is used as R1*1/4 in order to create the correct duration of the rest.  
Below is the relevant snippet. 

\version "2.12.0"

global = {
  \key c \major
  \time 3/4
}

right = \relative c'' {
  \global
  \override Staff.TimeSignature #'style = #'mensural
 \partial 4*1
 a4*1/4 g f g 
 \bar":" 
 a2*1/4 a b c b1*1/4 a g2*1/4 f1*1/4 e2*1/4
}

left = \relative c' {
  \global
  \override Staff.TimeSignature #'style = #'mensural
 R1*1/4 d2*1/4 d d a g a  c  b1*1/4 a  c2*1/4
}


\score {
  <<
    \new PianoStaff \with {
      instrumentName = "Organ"
    } <<
      \new Staff = "right"\right
      \new Staff = "left"  \left  >> >> }