This is a very interesting case of event handling. The jQuery library handles specific events in a special way, probably trying to escape certain scenarios. The change event, being one of them, is not handled in the traditional way. The FormDecorator attempts to fire this event, however, in IE if the event hasn't been attached the firing doesn't take place.
To work around this issue I advice you to use the Ajax Toolkit method for attaching event handlers, i.e. $addHandler. Using this method allows the FormDecorator to fire the event handlers correctly.
Hope this helps.
the Telerik team
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