High CPU Load

Hi All,

   I migrated Postgres server from 7.4.6 to 8.1.4, But my server is
completely full, by moment load average > 40

    All queries analyzed by EXPLAIN, all indexes are used .. IO is good ...

My configuration is correct ?

- default configuration and se + somes updates :

max_connections = 512
superuser_reserved_connections = 2
shared_buffers = 65536
work_mem = 65536
effective_cache_size = 131072
log_destination = 'syslog'
redirect_stderr = off
log_directory = '/var/log/pgsql'
log_min_duration_statement = 100
silent_mode = on
log_statement = 'none'
default_with_oids = on

My Server is Dual Xeon 3.06GHz with 2 Go RAM and good SCSI disks.

Best Regards,
Jérôme BENOIS.