ProgressText obsolete?

[Gosha]

When I try to set ProgressText with:

                <telerik:ReportViewer ID="ReportViewer1" runat="server"
                    ToolbarVisible="False" Height="100%" Width="100%" ProgressText="...">
                </telerik:ReportViewer>

or

ReportViewer1.ProgressText = "...."

I got error: 

'Public Property ProgressText As String' is obsolete: 'Use Resources.ProcessingReportMessage property instead or the resource file.'.

This is normaly worked until I updated Q1-2010 to Q1-2011 version!! What is wrong?