ties, polyphony and \alternative

[GoochRules!]

Greetings,

I am using lilypond 2.0.1-16 (from fink).
I wish to tie from a repeat to alternative endings from multiple voices 
in the same staff.  I've seen this post 
http://mail.gnu.org/archive/html/bug-lilypond/2004-01/msg00037.html, 
but I can't get it to work with multiple voices.

here's my notes:
\time 6/8 \key d \major
\repeat volta 2 {
        ...
        r8 << { a8[ a] a16[ d8. d16 d]~ } \\ { a8[ a] a16[ d8. d16 d]~ } >>
        %r8 a8[ a] a16[ d8. d16 d]~
}
\alternative {
        {
                d2.
                R2.*3
        }
        {
                \MkInvis d4~ \MkVis d2.*2/3
                R2.
        }
}

As you can see, the two voices are identical in the measure before the 
alternative endings, so I could use the commented line, but as an 
academic exercise, how would I mix polyphony, ties, and \alternative?  
If this works in later versions, then don't bother; I can wait until 
its a part of fink's stable branch.


--Matthew Peltzer