XElement root = XElement.Load(new XmlTextReader(respStream));
            var query = from XElement elem in root.Element("tasks").Elements("task")

                        //only well-formed nodes
                        where (
                            elem.Element("dateTime") != null &&
                            elem.Element("message") != null
                            )

                        //filter out invalid DateTime values
                        let parsed = ParseDateTime("dateTime")
                        where parsed != null

                        select new ReminderItem()
                        {
                            DateTime = parsed.GetValueOrDefault(),
                            Message = elem.Element("message").Value
                        };