Web.config: applicationName - When I change it, users cannot log in.

When I do the following users can no longer log in.  What have I done wrong here?  There is only one application in my aspnet_applications and users are all associated to it.

• In SQL: update aspnet.Applications set applicationName = '/app', set loweredApplicationName = '/app'
• In WEB.CONFIG: <add name="SqlRoleManager" type="System.Web.Security.SqlRoleProvider" connectionStringName="LocalSqlServer" applicationName="/app"/>

If I revert to just a "/" for applicationname, users can login again.  

Any help would be greatly appreciated.