03-JUL-2008 15:31:41 * (CONNECT_DATA=(ORACLE_SID=ora01)(SERVER=DEDICATED)(CID=(PROGRAM=C:\WINDOWS\system32\dllhost.exe)(HOST=testgl)(USER=testgl_terminal))) * (ADDRESS=(PROTOCOL=tcp)(HOST=129.142.228.155)(PORT=2388)) * establish * ora01 * 0
03-JUL-2008 15:31:44 * (CONNECT_DATA=(ORACLE_SID=ora01)(SERVER=DEDICATED)(CID=(PROGRAM=C:\WINDOWS\system32\dllhost.exe)(HOST=testgl)(USER=testgl_terminal))) * (ADDRESS=(PROTOCOL=tcp)(HOST=129.142.228.155)(PORT=2389)) * establish * ora01 * 0
03-JUL-2008 15:31:45 * (CONNECT_DATA=(ORACLE_SID=ora01)(SERVER=DEDICATED)(CID=(PROGRAM=c:\windows\system32\inetsrv\w3wp.exe)(HOST=testgl)(USER=IUSR_testgl))) * (ADDRESS=(PROTOCOL=tcp)(HOST=129.142.228.155)(PORT=2390)) * establish * ora01 * 0
03-JUL-2008 15:31:46 * service_update * ora01 * 0
03-JUL-2008 15:31:48 * (CONNECT_DATA=(ORACLE_SID=ora01)(SERVER=DEDICATED)(CID=(PROGRAM=C:\WINDOWS\system32\dllhost.exe)(HOST=testgl)(USER=testgl_terminal))) * (ADDRESS=(PROTOCOL=tcp)(HOST=129.142.228.155)(PORT=2392)) * establish * ora01 * 0

TNSLSNR for Linux: Version 10.2.0.1.0 - Production on 03-JUL-2008 16:20:30

Copyright (c) 1991, 2005, Oracle.  All rights reserved.

System parameter file is /home/oracle/product/10gR2/network/admin/listener.ora
Log messages written to /home/oracle/product/10gR2/network/log/listener.log
Trace information written to /home/oracle/product/10gR2/network/trace/listener.trc
Trace level is currently 0

Started with pid=15265
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=machine1.test.net)(PORT=1521)))
Listener completed notification to CRS on start

TIMESTAMP * CONNECT DATA [* PROTOCOL INFO] * EVENT [* SID] * RETURN CODE
WARNING: Subscription for node down event still pending
03-JUL-2008 16:20:30 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=machine11)(USER=oracle))(COMMAND=status)(ARGUMENTS=64)(SERVICE=LISTENER)(VERSION=169869568)) * status * 0

03-JUL-2008 16:20:30 * (CONNECT_DATA=(ORACLE_SID=ora01)(SERVER=DEDICATED)(CID=(PROGRAM=C:\WINDOWS\system32\dllhost.exe)(HOST=testgl)(USER=testgl_terminal))) * (ADDRESS=(PROTOCOL=tcp)(HOST=129.142.228.155)(PORT=1316)) * establish * ora01 * 12505
TNS-12505: TNS:listener does not currently know of SID given in connect descriptor
03-JUL-2008 16:20:34 * ping * 0
WARNING: Subscription for node down event still pending
03-JUL-2008 16:21:05 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=machine11)(USER=oracle))(COMMAND=status)(ARGUMENTS=64)(SERVICE=LISTENER)(VERSION=169869568)) * status * 0
03-JUL-2008 16:21:12 * (CONNECT_DATA=(ORACLE_SID=ora01)(SERVER=DEDICATED)(CID=(PROGRAM=C:\Documents and Settings\Administrator\Skrivebord\SQL Navigator 4\SQLNav4.exe)(HOST=testuser)(USER=Administrator))) * (ADDRESS=(PROTOCOL=tcp)(HOST=111.111.111.111)(PORT=31449)) * establish * ora01 * 12505
TNS-12505: TNS:listener does not currently know of SID given in connect descriptor
03-JUL-2008 16:21:12 * service_register * ora01 * 0
03-JUL-2008 16:21:21 * (CONNECT_DATA=(ORACLE_SID=ora01)(SERVER=DEDICATED)(CID=(PROGRAM=C:\Documents and Settings\Administrator\Skrivebord\SQL Navigator 4\SQLNav4.exe)(HOST=testuser)(USER=Administrator))) * (ADDRESS=(PROTOCOL=tcp)(HOST=111.111.111.111)(PORT=31456)) * establish * ora01 * 0
03-JUL-2008 16:21:28 * (CONNECT_DATA=(ORACLE_SID=ora01)(SERVER=DEDICATED)(CID=(PROGRAM=C:\Documents and Settings\Administrator\Skrivebord\SQL Navigator 4\SQLNav4.exe)(HOST=testuser)(USER=Administrator))) * (ADDRESS=(PROTOCOL=tcp)(HOST=111.111.111.111)(PORT=31457)) * establish * ora01 * 0
03-JUL-2008 16:21:34 * (CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=ora01)(CID=(PROGRAM=C:\Program Files\Quest Software\TOAD\TOAD.exe)(HOST=UTPALS)(USER=abhoite))) * (ADDRESS=(PROTOCOL=tcp)(HOST=203.199.150.10)(PORT=58514)) * establish * ora01 * 0
03-JUL-2008 16:21:39 * service_update * ora01 * 0
03-JUL-2008 16:22:00 * (CONNECT_DATA=(SERVICE_NAME=ora01)(CID=(PROGRAM=httpd2-prefork)(HOST=machine11)(USER=wwwrun))) * (ADDRESS=(PROTOCOL=tcp)(HOST=129.142.228.156)(PORT=46442)) * establish * ora01 * 0
03-JUL-2008 16:22:00 * service_update * ora01 * 0
03-JUL-2008 16:22:03 * service_update * ora01 * 0
03-JUL-2008 16:22:07 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=machine11)(USER=oracle))(COMMAND=services)(ARGUMENTS=64)(SERVICE=LISTENER)(VERSION=169869568)) * services * 0
WARNING: Subscription for node down event still pending

(PROGRAM=C:\WINDOWS\system32\dllhost.exe)

As a workaround, two steps should be done:

1. The following parameter can be added to listener.ora 

For example, if the listener name is LISTENER (default), the parameter would be: 

SUBSCRIBE_FOR_NODE_DOWN_EVENT_LISTENER=OFF

2. Locate the ons.config file in the 10g(rdbms) home and rename it to something else. 
For example: 
cd $ORACLE_HOME/opmn/conf 
mv ons.config ons.config.orig 

The listener needs to be restarted after these changes. 

# listener.ora Network Configuration File: E:\oracle\product\10.1.0\db_2\network\admin\listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = E:\oracle\product\10.1.0\db_2)
      (PROGRAM = extproc)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = test1.com)(PORT = 1521))
      )
    )
  )