Auto-vacuum parameters (Postgres 8.2 on Windows Server 2003)

["Christian Leclerc" <cleclerc(at)ilog(dot)fr>]

Hello,

I thought I set up correctly the pg_autovacuum daemon on according to the documentation available at the following URL:
http://www.postgresql.org/docs/8.2/static/routine-vacuuming.html
Please see below the parameters below set up in my postgresql.conf file. 
But the following message is systematically displayed as soon as I insert or update lots of rows in my tables when I browse my tables with pgAdmin :
"Running VACUUM recommended
The estimated rowcount on the table "sales_admin.maintenance_contract_lines" deviates significantly from the actual rowcount. You should run VACUUM ANALYZE on this table.
Instead of issuing a manual VACUUM ANALYZE command on this table (you can use the pgAdmin III maintenance menu for this), running VACUUM ANALYZE on a regular or automated basis should be considered. This can be achieved using a scheduler. PostgreSQL also supplies the pg_autovacuum daemon, which will track changes made to the database and issue vacuum commands as required automatically. In most cases, pg_autovacuum will be the best choice"

What I'm doing wrong?

Thanks,
Christian


#---------------------------------------------------------------------------
# RUNTIME STATISTICS
#---------------------------------------------------------------------------

# - Query/Index Statistics Collector -

#stats_command_string = on
#update_process_title = on

stats_start_collector = on              # needed for block or row stats
                                        # (change requires restart)
#stats_block_level = off
stats_row_level = on
#stats_reset_on_server_start = off      # (change requires restart)


# - Statistics Monitoring -

#log_parser_stats = off
#log_planner_stats = off
#log_executor_stats = off
#log_statement_stats = off

#---------------------------------------------------------------------------
# AUTOVACUUM PARAMETERS
#---------------------------------------------------------------------------

autovacuum = on                 # enable autovacuum subprocess?
                                        # 'on' requires stats_start_collector
                                        # and stats_row_level to also be on
#autovacuum_naptime = 1min              # time between autovacuum runs
#autovacuum_vacuum_threshold = 500      # min # of tuple updates before
                                        # vacuum
#autovacuum_analyze_threshold = 250     # min # of tuple updates before
                                        # analyze
#autovacuum_vacuum_scale_factor = 0.2   # fraction of rel size before
                                        # vacuum
#autovacuum_analyze_scale_factor = 0.1  # fraction of rel size before
                                        # analyze
#autovacuum_freeze_max_age = 200000000  # maximum XID age before forced vacuum
                                        # (change requires restart)
#autovacuum_vacuum_cost_delay = -1      # default vacuum cost delay for
                                        # autovacuum, -1 means use
                                        # vacuum_cost_delay
#autovacuum_vacuum_cost_limit = -1      # default vacuum cost limit for
                                        # autovacuum, -1 means use
                                        # vacuum_cost_limit