SQL 2000 Authentication From Windows 2003

I'm working on deploying an ASP.NET 2.0 app onto a Windows 2003 server and I'm having trouble with SQL 2000 authentication. When I run my app from my development box running IIS 5.1 I have no problems. In order to get it to work on my this machine, I had set the account for anonymous access to run under an ASPNETDOMAIN account and configured my SQL database to allow this account.

On the Windows 2003 box with IIS 6.0, I've done the same thing with anonymous access for the web app, and also created an application pool that the app runs under and have set the application pool to run under the same account. It appears the app is looking for a local SQL 2005 instance (which doesn't exist). Why would it do this and what do I need to change for this to work?

Error:An error has occurred while establishing a connection to
the server.  When connecting to SQL Server 2005, this failure may be
caused by the fact that under the default settings SQL Server does not
allow remote connections. (provider: SQL Network Interfaces, error: 26
- Error Locating Server/Instance Specified)
Stack Trace:
[SqlException (0x80131904): An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)]
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +735043
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +188
System.Data.SqlClient.TdsParser.Connect(Boolean& useFailoverPartner, Boolean& failoverDemandDone, String host, String failoverPartner, String protocol, SqlInternalConnectionTds connHandler, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject, Boolean aliasLookup) +820
System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +628
System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +170
System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +130
System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup) +27
System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +47
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +105
System.Data.SqlClient.SqlConnection.Open() +111
System.Web.Management.SqlServices.GetSqlConnection(String server, String user, String password, Boolean trusted, String connectionString) +68