Has anyone had success implementing an ASP.NET 2.0 appliction to use windows authentication via Micorosoft's trusted subsystem model to connect to an Oracle database? I have the model working for our application connecting to a SQL Server database as the msdn article details, but have an odd issue with the implementation when connecting to an Oracle database.

The issue is that the first browser session to a page that attempts to connect to the database always fails with an Oracle error "ORA-01017: invalid username/password; logon denied". All further browser session to the same page have successfull connections to the Oracle database as the domainname\machinename$ as expected and work fine. So what is happening that the first attempt to connect with integrated security always fails?

Windows 2003/IIS 6 web server
.NET 2.0 application (using the Microsoft managed provider for Oracle System.Data.OracelClient)
Connection string is "Data Source=myDB;Persist Security Info=False;Integrated Security=Yes;"
Oracle 10g database
domainname\webservermachinename$ is setup as a user in the Oracle database.