Has anyone seen strange behavior with DNN 4.82 and postbacks ?

My view state is being trashed and a postback actually gets turned into page refresh by one of the core controls !!!

The following event is being raised from the IconBar.ascx.vb file when posting back from a button on the page.

        Protected Sub optMode_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles optMode.SelectedIndexChanged
            If Not Page.IsCallback Then
                SetMode(True)
                Response.Redirect(Request.RawUrl, True)
            End If
        End Sub

I have RADMenu installed and a custom skin that I will be looking at in detail. I had to fallback to an earlier DNN version to get things working again.