I think I've got it.  The argument that says:  "90% of the people will
see double-sixes" occurs AFTER the experiment terminates.  If such an
experiment has been performed and you are told that you will be assigned
to some post-hoc group at random, odds are 90% that you will see double
sixes and you should bet that way.
If you're walking into the room and the dice are just being rolled,
chances are 1 in 36 that two sixes show.  There isn't a pool of victims
to be randomly picked from yet.
Or so I see it...
-- 
         sentience@pobox.com      Eliezer S. Yudkowsky
          http://tezcat.com/~eliezer/singularity.html
           http://tezcat.com/~eliezer/algernon.html
Disclaimer:  Unless otherwise specified, I'm not telling you
everything I know.