Add support for Widow/Orphan control property of Paragraph. In Open XML specification, this is named "widowControl (Allow First/Last Line to Display on a Separate Page)". The problem is that as this property is not supported, RadRichTextBox acts as it's 'false' and also doesn't export it, but the default value is actually 'true', which causes layout differences between RadRichTextBox and MS Word.
This item is declined as duplicate of http://feedback.telerik.com/Project/143/Feedback/Details/112798 Your votes are already transferred there.