Convert または datetime 文字列の受け渡しが datetiem2(0) フィールドで機能しない理由は、クエリです。
SELECT IsNull(Max(SOURCE_CODE), 'UNKNOWN') source_code,
FROM Table1
WHERE
--DATE_INSERTED between CONVERT(DATETIME,'10/01/2013') AND CONVERT(DATETIME,'10/31 /2013')
DATE_INSERTED >='2013-10-10 00:00:01 AM' AND DATE_INSERTED <= '2013-10-31 23:59:59 PM'
AND (SOURCE_CODE IS NOT NULL) AND
(RESULT_CODE = 0 OR RESULT_CODE = 100) GROUP BY SOURCE_CODE