If I take out the pagesize from the datapager then the grouping works, however then you cannot page the data. If I set this to 10 then the grouping goes over 2 pages [first group does contain 10 records, second group contains 1 record].
See What's New in RadControls for Silverlight in Q3 2010 on Tuesday, November 16, 2010 11:00 AM - 12:00 PM EST or 10:00 PM - 11:00 PM EST: Register here>>