Problem connecting to database with Integrated security=SSPI

I am having a problem connecting from a web server to a SQL 2005 database.  When my connection string includes 'Integrated security=SSPI;' , I recive the following error -

Cannot open database "*******" requested by the login. The login failed.

Login failed for user 'NT AUTHORITY\NETWORK SERVICE'.

I am using .nettiers 2.0. 

Here is my connection information -

<configSections>
        <section name="*******.Data" type="*******.Data.Bases.NetTiersServiceSection, ********.Data" allowDefinition="MachineToApplication" restartOnExternalChanges="true"/>
        <section name="enterpriseLibrary.ConfigurationSource" type="Microsoft.Practices.EnterpriseLibrary.Common.Configuration.ConfigurationSourceSection, Microsoft.Practices.EnterpriseLibrary.Common, Version=2.0.0.0, Culture=neutral, PublicKeyToken=null"/>
    </configSections>
    <appSettings>
        <add key="****" value="user id=*****; password=*******; server=********; database=********;"/>
    </appSettings>

    <connectionStrings>
  <add name="********.Data.ConnectionString" connectionString="Data Source=*********;Initial Catalog=********;Integrated security=SSPI;user id=*********; password=*********;Connection Timeout=1;" />
  <add name="ConnectionString" connectionString="Data Source=********sql2005;Initial Catalog=********;Integrated security=SSPI;user id=********; password=*********"
   providerName="System.Data.SqlClient" />
    </connectionStrings>

 The same error is thrown if I use 'Integrated security=True;'.  If I take this out (which I don't think i want to do), the connection is made.

 
I have a user with the appropriate permissions set up in SQL that I am trying to connect through.

Please let me know what I am missing as I am new to .nettiers