After installing the VSTS Database GDR and importing a SQL Server 2005 database that includes the ASP.NET provider schema tables, I get the following warnings:
Kim's answer above works perfectly for the situation I asked for. But, I also found out that you can filter the build warnings per file. Look at http://blogs.msdn.com/gertd/archive/2009/01/11/file-level-build-warning-suppression-in-the-gdr.aspx