I can do tnsping to both the dbs

See the below error. That's very strange:

LSNRCTL> status
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias LISTENER_GISDEVVersion TNSLSNR for 64-bit Windows: Version 11.2.0.1.0 - Production
Start Date 25-JAN-2011 08:36:39
Uptime 0 days 3 hr. 8 min. 6 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File C:\ORA\dbadmin\product\11.2.0\GISDEV\NETWORK\ADMIN\listener.ora
Listener Log File c:\ora\dbadmin\diag\tnslsnr\PDFPGISORDEV\listener_gisdev\alert\log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=PDFPGISORDEV.PADOTGIS.state.pa.us)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC1521ipc)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "giszgg" has 1 instance(s).
Instance "gisdev", status READY, has 2 handler(s) for this service...
The command completed successfully
LSNRCTL>
LSNRCTL>
LSNRCTL>
LSNRCTL>
LSNRCTL>
LSNRCTL>
LSNRCTL> start listener_giszgg
TNS-01106: Listener using listener name LISTENER_GISDEV has already been started
LSNRCTL>
++++++++++++++++++++++++++++++++++++++++++++++++++

C:\ORA\dbadmin\product\11.2.0\GISDEV\BIN>tnsping gisdev

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 25-JAN-2011 11:42:36

Copyright (c) 1997, 2010, Oracle. All rights reserved.

Used parameter files:
C:\ORA\dbadmin\product\11.2.0\GISDEV\NETWORK\ADMIN\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 164.156.155.134)(PORT = 1521)) (CONNECT_DATA = (SERVER = SHARED) (SERVICE_NAME = gisdev)))
OK (0 msec)

C:\ORA\dbadmin\product\11.2.0\GISDEV\BIN>tnsping giszgg

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 25-JAN-2011 11:42:43

Copyright (c) 1997, 2010, Oracle. All rights reserved.

Used parameter files:
C:\ORA\dbadmin\product\11.2.0\GISDEV\NETWORK\ADMIN\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 164.156.155.134)(PORT = 1521)) (CONNECT_DATA = (SERVER = SHARED) (SERVICE_NAME = giszgg)))
OK (10 msec)

C:\ORA\dbadmin\product\11.2.0\GISDEV\BIN>


++++++++++++++++++++++++++++++++++++++++++++++++++++++++

and the listener.ora is:

SID_LIST_LISTENER_GISDEV =
(SID_LIST =
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = C:\ORA\dbadmin\product\11.2.0\GISDEV)
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ONLY:C:\ORA\dbadmin\product\11.2.0\GISDEV\bin\oraclr11.dll")
)
)

LISTENER_GISZGG =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = PDFPGISORDEV.PADOTGIS.state.pa.us)(PORT = 1521))
)
)

ADR_BASE_LISTENER_GISDEV = C:\ORA\dbadmin

ADR_BASE_LISTENER_GISZGG = C:\ORA\dbadmin

LISTENER_GISDEV =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = PDFPGISORDEV.PADOTGIS.state.pa.us)(PORT = 1521))
(ADDRESS = (PROTOCOL = TPC)(KEY = EXTPROC1521))
)
)