ORA-06413 Connection not open

Help!

I have a 64 bit Windows 2008 R2 SP1 server (Citrix XenApp) and I'm trying to connect to an Oracle database 10g through a 32 bit ODBC connection (Microsoft ODBC for Oracle).  I'm receiving an ORA-06413 Connection Not Open error.

The App is an Excel 2010 (32 bit) macro using ADODB to open an ODBC connection.
   Dim ConString, SQL
    Dim Conn As New ADODB.Connection
    Dim rs As New ADODB.Recordset
   
    Set Conn = New ADODB.Connection
    ConString = "Provider=MSDAORA.1;Data Source=prtl;User ID=rate;Password=******"
   
    Conn.Open ConString

I get the error as soon as I try to open the connection.  I've also tried creating a connection in Access 2003 via ODBC and I get the same error.

This same Excel spreadsheet works on a Windows 2003 R2 machine running Excel 2003.  However it's using a different Oracle Client (6i) and it's pure 32 bit.

The Oracle client that was installed is the 32 bit Oracle Developer Suite 10g (10.1.2.0.2).
 
I've verified that TNS is working using tnsping as well as I can connect to SQL*plus.

I found a bunch of old articles on this error, but nothing is panning out.  The only thing I've tried is copying the oracle folder in (x86) to program files and then I removed the (x86) reference in the registry under the Oracle key.  That didn't work.

Thanks in advance for any help,

Steve Cross