Listener shuts itself down after a minute

Oracle 8.1.7, solaris 7. I do a 'lsnrctl start' and everything starts just fine. I can then 'sqlplus system/manager_at_admin1' and get connected. But after a minute or two the listener shuts itself down. I set TRACE_LEVEL_LISTENER = 16 and I've looked at the listener.log and listener.trc files and I can't figure out any problems.

Actually, sometimes when I do a 'sqlplus system/manager_at_admin1' after I start the listener I get an ORA-12154 error, but that too goes away after a little while, then I can connect to the database (without changing anything), then a minute or two later the listener totally dies.

This has really got me baffled. Any help much appreciated...

Allen

ps, here is my listener.ora file:

LISTENER2 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.0.0.57)(PORT = 1521))   )

SID_LIST_LISTENER2 =
  (SID_LIST =
    (SID_DESC =
(GLOBAL_DBNAME = admin1.world)
(ORACLE_HOME = /export/home/oracle/app/product/8.1.7)
(SID_NAME = admin1)

    )
  )

TRACE_LEVEL_LISTENER = 16 and here is my tnsnames.ora file:

ADMIN1 =
  (DESCRIPTION =
    (ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.0.0.57)(PORT = 1521))
    )
    (CONNECT_DATA =
(SERVICE_NAME = admin1.world)

    )
  ) Received on Wed Aug 22 2001 - 03:15:04 CDT