TNSPING works but an ORA-12154 error on SQLPLUS

I have three systems 1 Windows 2000 and the other 2 running Linux.  The ORACLE server is a LINUX server 192.168.1.220 (MDLITTLE).  The other Linux system is a client that boot from a CD that is created from the server.  For the oracle client I install the standard oracle9i client software into /home/oracle9i and then tar the information and move it into the CD directory.  

I can access the ORACLE database without problem on the Linux server and from the Window 2000 system.  Yet I receive an error from the Linux client.  I have the following files.

Window 2000 client:  tnsnames.ora
# TNSNAMES.ORA Network Configuration File: C:\oracle\ora92\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

PROACT =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.220)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = proact.proactivemonitoring.com)
    )
  )

Window 2000 client: sqlnet.ora
# SQLNET.ORA Network Configuration File: C:\oracle\ora92\network\admin\sqlnet.ora
# Generated by Oracle configuration tools.

SQLNET.AUTHENTICATION_SERVICES= (NTS)

NAMES.DIRECTORY_PATH= (TNSNAMES)

On the Linux server that works I have:
/home/oracle9i/network/admin/tnsnames.ora:
# TNSNAMES.ORA Network Configuration File: /home/oracle9i/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.

PROACT =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.220)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = proact.proactivemonitoring.com)
    )
  )

/ home/oracle9i/network/admin/sqlnet.ora
# SQLNET.ORA Network Configuration File: /home/oracle9i/network/admin/sqlnet.ora
# Generated by Oracle configuration tools.

NAMES.DIRECTORY_PATH= (TNSNAMES, ONAMES, HOSTNAME)

Results from the test:
TNS Ping Utility for Linux: Version 9.2.0.1.0 - Production on 12-FEB-2003 11:48:20

Copyright (c) 1997 Oracle Corporation.  All rights reserved.

Used parameter files:
/home/oracle9i/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.220)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = proact.proactivemonitoring.com)))
OK (10 msec)

SQL*Plus: Release 9.2.0.1.0 - Production on Wed Feb 12 11:48:48 2003

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.


Connected to:
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production

SQL> Disconnected from Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production

The Linux client system that does not work has:
/home/oracle9i/network/admin/tnsnames.ora:
# TNSNAMES.ORA Network Configuration File: /home/oracle9i/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.

PROACT =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.220)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = proact.proactivemonitoring.com)
    )
  )

/ home/oracle9i/network/admin/sqlnet.ora
# SQLNET.ORA Network Configuration File: /home/oracle9i/network/admin/sqlnet.ora
# Generated by Oracle configuration tools.

NAMES.DIRECTORY_PATH= (TNSNAMES, ONAMES, HOSTNAME)

Results from the tests are:
TNS Ping Utility for Linux: Version 9.2.0.1.0 - Production on 12-FEB-2003 01:43:57

Copyright (c) 1997 Oracle Corporation.  All rights reserved.

Used parameter files:
/home/oracle9i/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.220)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = proact.proactivemonitoring.com)))
OK (10 msec)

SQL*Plus: Release 9.2.0.1.0 - Production on Wed Feb 12 01:45:14 2003

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

ERROR:
ORA-12154: TNS:could not resolve service name


Enter user-name: ERROR:
ORA-06413: Connection not open.


Enter user-name: ERROR:
ORA-06413: Connection not open.


SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus

On both Linux server and client I used the oracle user with the bash shell.  Also in both cases I have a .bash_profile file with:
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
      . ~/.bashrc
fi

# User specific environment and startup programs

ORACLE_BASE=/home/oracle9i; export ORACLE_BASE
ORACLE_HOME=/home/oracle9i; export ORACLE_HOME
ORACLE_SID=proact; export ORACLE_SID
PATH=$PATH:$ORACLE_HOME/bin; export PATH
LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib:/usr/local/lib; export LD_LIBRARY_PATH
unset USERNAME


From the above error ORA-12154 you would think that the tnsnames.ora file is not found.  I do not understand why not since the tnsping can find the file.

Can anyone help?