PD_ALL_VISIBLE flag error on 9.0 alpha 4

All,

What I did:

1. Set up 9.0a4 doing SR replication with a 2nd 9.0a4
2. Ran pgbench for a while.
3. Aborted pgbench with Ctl-C
4. Changed vacuum_defer_cleanup_age in postgresql.conf and reloaded
5. Ran pgbench again, and got:

Sidney-Stratton:pg90 josh$ pgbench -c 2 -T 300 bench
starting vacuum...WARNING:  PD_ALL_VISIBLE flag was incorrectly set in
relation "pgbench_branches" page 0
WARNING:  PD_ALL_VISIBLE flag was incorrectly set in relation
"pgbench_branches" page 1
WARNING:  PD_ALL_VISIBLE flag was incorrectly set in relation
"pgbench_tellers" page 0
WARNING:  PD_ALL_VISIBLE flag was incorrectly set in relation
"pgbench_tellers" page 1

... not one I'm familiar with.  Issues?

--Josh Berkus