Oracle 10:1:0:200 client works on windows 2003 not XP

Question

Hi Group,
The backend oracle database is the same. The Serviced Components Middle Layer is on Windows 2003 and XP Professional SP1. The Clients are tested on the Middle Layer.
It works fine on Windows 2003. On XP the error is:
================
Failed to Open the Data Source connection error: Oracle.DataAccess.Client.OracleException ORA-01453: SET TRANSACTION must be first statement of
transaction at Oracle.DataAccess.Client.OracleException.HandleErrorHelper(Int32 errCode, OracleConnection conn, IntPtr opsErrCtx, OpoSqlValCtx* pOpoSqlValCtx, Object src, String procedure)
at Oracle.DataAccess.Client.OracleCommand.ExecuteNonQuery()
================
thanks,
-Arvinder

Answer 1

The problem does not have to do with XP/Windows 2003. It is caused by:
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OracleCommand cmd = new               
OracleCommand("SET TRANSACTION ISOLATION LEVEL READ COMMITTED", cnn);
cmd.ExecuteNonQuery();
==========
The COM+ transactions are defaulted to serializable. Our application reads a config file to choose the database and then issues the statement above. I know we can set the isolation attribute at the c# serviced component level at compile time. Is there a dynamic way to set the isolation at runtime? Microsofts SQL and Oracle providers do not fail with the SQL statement above.
thanks,
-Arvinder