position of rehearsal mark affected by \acciaccatura

[Ken Ferry]

Hi,

With this snippet,

\time 3/4 <<
  {  g2~( g8 d)| \mark \default d2.~}
  {  a8( b~ b2)| \mark \default \acciaccatura b8 c4.} >>

two rehearsal marks are printed.  If I move the mark to the other side of the 
acciaccatura like so:

\time 3/4 <<
  {  g2~( g8 d)| \mark \default d2.~}
  {  a8( b~ b2)| \acciaccatura b8 \mark \default c4.} >>

then the mark no longer prints over the barline.

It seems to me that the acciaccatura should have no affect on the position 
of the mark.

I'm running Lilypond 2.8.7 on Mac OS X 10.4.7 ppc.

Cheers,
Ken

PS - I had to mangle my notation to convince the bug submission form 
that I'm not top posting.  Can the requirements be turned down a little?