Unfortunately no improvement.
It just sits spinning its wheels. If I try to start a secong upload the progress indicator (spinning icon) appears.
Would be good if it showed initially.
However the final result is the error message mentioned earlier
Silverlight : The upload task is interrupted!Unable to get web http response.System.Net.WebException: The remote server returned an error: NotFound at System.Net.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult) at System.Net.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at Silverlight.FileItem._OnGetResponse(IAsyncResult ar)