Thank you, Mark.
See gr-qc/0205035 for my approach.
Ilja
There is a number of penetrating papers by J. Barbour
http://arxiv.org/abs/gr-qc/0309089
http://arxiv.org/abs/gr-qc/0012089 (and other related papers
cited in the first reference above),
as well as his book "The End of Times", (Oxford Univ Press, 2000).
See also http://arxiv.org/abs/gr-qc/0610061 (pages 107-163),
and a recent work http://arxiv.org/abs/0712.3660
for my approach.