The initial resolution on all this is that it's another instance of a
really tricky bug that should be resolved now. Long description of the
problem is at
http://archives.postgresql.org/message-id/17311.1305080416@sss.pgh.pa.us
Thanks for the report, and if you could check this again on 9.1 Beta 2
after it's released to confirm the fix holds, that would be helpful.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us