I noticed that in the demo of load on demand at http://samples.infragistics.com/2010.1/WebFeatureBrowser/Default.aspx, you can't type and find an item that hasn't been loaded into the list box yet (like paris in the demo).  If you use the drop-down button and scroll to the very bottom of the list to load everything, and then start typing something, it'll autocomplete.

Is this a bug in the demo or the actual behavior of the drop down?  It seems to be a major bug and is one reason I haven't implemented this control yet and am thinking of using Telerik.