We can confirm that we had an issue with RowIsExpandedChanged in Q2 2010 SP1 version - the one pointed by you. But, it was fixed with the next official release - Q2 2010 SP2 (.0924). Is it possible to you to upgrade to this version or to our latest official version - Q3 2010 SP1 (.1314) so that you would be able to implement Load on demand approach ?
the Telerik team
Registration for Q1 2011 What’s New Webinar Week is now open. Mark your calendar for the week starting March 21st and book your seat
for a walk through all the exciting stuff we ship with the new release!