DataSource Controls :: Cannot Find The Object 'AspNet_SqlCachePollingStoredProcedure'?

I have a Windows 2003 test server hosting an asp.net 2.0 application and Sql Server 2005 running as Sql Server 2000(80).During a recent a security review we decided that it wasn't such a hot idea to use sql authentication with an sysadm user as the database user for the asp.net application. Having done a bit of reading (http://msdn.microsoft.com/en-us/library/ms998258.aspx#pagguidelines0001_dataaccess) I decided to use a lower privilege database user account and windows authentication.Starting from scratch I created a new custom service account (http://msdn.microsoft.com/en-us/library/ms998297.aspx) and assigned this to the process identity for the application pool.I then created a new database login and user for this account. I added the db_datareader and db_datawriter roles to this user and I also granted EXECUTE permissions for user defined stored procedure and functions. However when I started the application I got this error 'User does not have permission to perform this action.Cannot find the object 'AspNet_SqlCachePollingStoredProcedure', because it does not exist or you do not have permission.' - after a quick hunt I found thishttp://forums.asp.net/p/1487216/3493362.aspx and followed the advice herehttp://msdn.microsoft.com/en-us/library/system.web.caching.sqlcachedependencyadmin.aspx and granted the user CREATE TABLE and CREATE PROCEDURE permissions.Still no joy - after digging around and looking at sql profiler I found what I believe to be the offending piece of sql:

/* Create notification table */
...sql
/* Create polling SP */
..more sql
..finally
GRANT EXECUTE ON dbo.AspNet_SqlCachePollingStoredProcedure to aspnet_ChangeNotification_ReceiveNotificationsOnlyAccess

My understanding is that to issue 'GRANT EXECUTE' the user must db_owner or db_secadmin. Indeed it all works fine if I give the service account user login the db_owner role.This sql is caused by: SqlCacheDependencyAdmin.EnableNotifications(ConnectionString), this is called once and once only by the application start event.Is there a work around for this? I would like to use the lower privilege account as per best practice but this issue is making it tricky.