I had created a stored procedure that included bulk insert statements. The bulk insert needed to access .txt files from a secure folder. An SQL Agent ran the stored procedure under the sqlservice account. Before testing the SQL Agent, we modified the security settings of the secure folder to allow the sqlservice account to read from the folder. A test was run and the stored procedure generated an error stating that is could not access a .txt file in the secure folder. Why was the stored procedure unable to access the .txt file in the secure folder? It turns out in order for the new folder permissions granted to the sqlservice account to take hold, the SQL Server instance where the SQL Agent ran needed to be restarted. After we restarted the SQL Server instance, the stored procedure was then able to access the files in the secure folder.
From Pete Brown's blog, here is an excellent video by Jason Dolinger on MVVM.