title: Umbraco richtext is not saved after upgrading to 4.11
body: <p>I upgraded from Umbraco 4.10 to 4.11 and now when I save a document, all fields are saved except for richtext fields where everything is deleted. Anything I type in richtext editor is lost after saving.<br>
  I've had similar problems before with other editors which were caused by html elements and could be solved by uri encoding but I never had this problem with Umbraco and TinyMce.  </p>