11.2 RAC DBconsole Creation Fails With Error: "Invalid username/password or database/scan listener not up" (Doc ID 1276751.1)

Creating RAC DBConsole failing with following error:

emca -config dbcontrol db -repos create -cluster

=============
STARTED EMCA at Dec 23, 2010 5:08:26 PM
EM Configuration Assistant, Version 11.2.0.0.2 Production
Copyright (c) 2003, 2005, Oracle. All rights reserved.

Enter the following information:
Database unique name: <DB_NAME>
Service name: <DB_NAME>
Listener port number: 1561
Listener ORACLE_HOME [ <GRID_HOME> ]: <DB_HOME>
Password for SYS user:
Password for DBSNMP user:
Password for SYSMAN user:
Cluster name: crs
Email address for notifications (optional):
Outgoing Mail (SMTP) server for notifications (optional):
ASM ORACLE_HOME [ <GRID_HOME> ]:
ASM port [ 1561 ]: 1521
ASM username [ ASMSNMP ]:
ASM user password:
Invalid username/password or database/scan listener not up or database service is not registered with scan listener.
ASM user password:
===============

Following are the errors logged in emca log:
============
Dec 23, 2010 5:10:36 PM oracle.sysman.emcp.util.GeneralUtil initSQLEngineRemotely
CONFIG: SQLEngine connecting with Service Name: +ASM, oracleHome: <GRID_HOME>, and user: ASMSNMP host: <RAC_INSTANCE_NODE1> port: 1561
Dec 23, 2010 5:10:37 PM oracle.sysman.emcp.util.GeneralUtil initSQLEngineRemotely
CONFIG: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor

oracle.sysman.assistants.util.sqlEngine.SQLFatalErrorException: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor

at oracle.sysman.assistants.util.sqlEngine.SQLEngine.executeImpl(SQLEngine.java:1655)
...
Dec 23, 2010 5:10:43 PM oracle.sysman.emcp.util.GeneralUtil initSQLEngineRemotely
CONFIG: SQLEngine connecting with Service Name: +ASM, oracleHome: <GRID_HOME>, and user: SYS host: <RAC_INSTANCE_NODE2> port: 1561
Dec 23, 2010 5:10:43 PM oracle.sysman.emcp.util.GeneralUtil initSQLEngineRemotely
CONFIG: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor
===========