Judging by official documentation, see second NOTE:
http://www.granitedataservices.com/public/docs/3.1.0/docs/reference/flex/graniteds-refguide-flex.html#reflection.appdomainThe problem is because an entity's class is "registered" or something in multiple ApplicationDomain's (analogue of java ClassLoaders). And when we're trying to load an instance of this class Granite throws exception at line 182 from the source code above. For now, I don't know how to make Granite and multiple loaded swf/swc friends. Since then, I have to go away of ChangeSet mechanism for a while.
If anyone have a solution, please, share it.