Oracle Instant Client Connectivity

[harmony_wsc]

I continue to get the following warning trying to connect to an Oracle DB on a different server.

Warning: ocilogon() [function.ocilogon]: ORA-12170: TNS:Connect timeout occurred in ...

Environment
Windows Server 2003 SP2
PHP 5.2.5
IIS 6.0
Oracle Instant Client 11.1

I have the path to Instant Client in my PATH variable after my path to PHP. I can successfully ping the server with the Oracle DB running. Does anyone have any ideas on how I can resolve this?

[harmony_wsc]

Also, I have verified that my DB and Listener are running on the DB server.