Getting an OLEDB Transaction for Oracle 7.2

[Sara]

I am getting an error that states: DB_E_ERRORSINCOMMAND when I try to
establish a transaction in an Oracle 7.2 database. The code is:

Try
If AuthHelper.App_conn.State = ConnectionState.Closed Then
AuthHelper.App_conn.Open()
End If

Dim myTrans As
System.Data.OleDb.OleDbTransaction=AuthHelper.App_ conn.BeginTransaction()

test_results.Transaction = myTrans
Catch..etc,etc

Well, anyway, it's wordwrapping but the line that starts 'Dim myTrans'
throws the above error. I've tried it with Isolation levels, and the
isolation level 'Unspecified' gives me a different error message. That
one says that the Isolation level is not supported.
Can anyone help????
-Sara