To do this you should get a reference to the RadDock's resize extender object, and disable the automatic scrolling of the browser's viewport. This is done on the client:
dock = $find(
rExtender = dock._resizeExtender;
the Telerik team
Register for the Q2 2011 What's New Webinar Week. Mark your calendar for the week starting July 18th and book your seat for a walk through of all the exciting stuff we will ship with the new release!