Force removing Locks

Hello,

I've got a Problem... An Application that uses my Postgres Server always
keeps some locks open... Is there a Possibility to forcing remove the
Locks after a certain Interval or to remove them by hand? Because of
this Locks autovacuum cant work properly on this table and finally
System runs out of Disk Space...

Here is my pg_locks table:
===========================================================================
postgres=# SELECT locktype, relation, pid, mode, granted FROM
pg_catalog.pg_locks;
locktype | relation | pid | mode | granted
---------------+----------+-------+--------------------------+---------
relation | 7691926 | 9218 | ShareUpdateExclusiveLock | t
relation | 7691926 | 11652 | RowShareLock | t
relation | 7691926 | 11652 | RowExclusiveLock | t
virtualxid | | 11652 | ExclusiveLock | t
relation | 7691931 | 9218 | RowExclusiveLock | t
virtualxid | | 21255 | ExclusiveLock | t
relation | 9681822 | 11652 | AccessShareLock | t
virtualxid | | 9218 | ExclusiveLock | t
relation | 7691929 | 9218 | ShareUpdateExclusiveLock | t
transactionid | | 11652 | ExclusiveLock | t
relation | 9681826 | 11652 | AccessShareLock | t
relation | 10969 | 21255 | AccessShareLock | t
(12 Zeilen)

=============================================================================

Thank you
Regards,
Flo