To make your code work you have to do all of the following:
1. Add a parameterless constructor.
2. Change the TimeSpan data type (string will work).
3. Change all XmlAttribute attributes to XmlElement attrbutes.
4. Remove the
xmlns
=
"
http://tempuri.org/
"
part (I don't know what it's supposed to mean but it's not syntactically correct).
Otherwise you'll get an exception. (I don't know why you're not actually seeing any exceptions -- perhaps you're running this code in a background thread?)