BUG #6167: pg_dump fails on table lock

The following bug has been logged online:

Bug reference: 6167
Logged by: Jesper Engman
Email address: jesper(at)engman(dot)net
PostgreSQL version: 8.3.10
Operating system: Linux
Description: pg_dump fails on table lock
Details:

I have tables that exists for short time periods, sometimes for as short as
5 min. pg_dump is starting to fail due to a problem to lock these tables:

pg_dump: SQL command failed
pg_dump: Error message from server: ERROR: relation
"vehicle_change_partitions.vehicle_change_export_p4368494" does not exist
pg_dump: The command was: LOCK TABLE
vehicle_change_partitions.vehicle_change_export_p4368494 IN ACCESS SHARE
MODE
Backup failed: PGPASSWORD=xxxxx && export PGPASSWORD && export PGOPTIONS="-c
statement_timeout=0 -c maintenance_work_mem=2147483647" && /usr/bin/pg_dump
-h xxx.xxx.xxx.xxx -U postgres --ignore-version -Fc -Z 6 xxxxxxxx >
/vol/nfs_backup/postgres_dumps/2011_07_13/xxxxxxxx_2011_07_13
Account: xxxxxxxx Backup failed

How is this possible - pg_dump is a serializable transaction? It doesn't
seem to be tripped up by some other backend function since this actually
fails on the lock.