Could you clarify whether your RadListView is ajaxified or not? If you are using Ajax, then you should disable it when uploading files since the RadUpload could not upload files via Ajax. Another approach would be to use RadAsyncUpload control instead.
All the best,
the Telerik team
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the RadControls for ASP.NET AJAX, subscribe to their blog feed