Connecting to TD15 from Visual Basic

I have an Excel tool that I use that connects to Teradata and brings back database information to the spreadsheet. This has been working just fine with the following connection string:-
' Create the Connection object
    Set Conn = New ADODB.Connection
    strConn = "PROVIDER=MSDASQL;DRIVER={Teradata};DBCName="& systm & ";User ID="& UID & ";Password="& pswd & ";"
' Assign the connection string and provider, then open the Connection
    Conn.ConnectionString = strConn
    Conn.Provider = "teradata"
    Conn.Open strConn
However, when I recently upgraded my TTU drivers to TD15 then it stopped working and I started getting the following error:
                Runtime error '-2147217843 (80040e4d)':
                [Teradata][Teradata ODBC Driver] Not enough information to log on
I tried changing the connection string to accept the additional information that TD15 is looking for and then I get an error in the VB code saying that there are too many parameters.
Anyone had this problem and know how to fix it?