Thanks, I just investigated this, but it looks like it did not fix the problem.
In 8.4.6 Postgres changed the default "wal_sync_method" to "fdatasync," because the old default "open_datasync" failed on ext4. I use ext3 (on ubuntu 9.10), but I tried changing this option in my postgres database anyway. I changed it, restarted postgres and apache, but still get the error.
