OK I keep getting this error after about 3-4 minutes of churning:
Timeout expired. The timeout period elapsed prior to completion of the operation or the s
It looks like the timeout is happening when you're running the sql stored procedure (Your exception is of type SqlException). You would need to increase the Timeout of your Sql Stored Procedure execution, but I don't think you can do that with the SqlHelper class.
You'll need to go with the SqlCommand class, and set the timeout there.