Joe, thank you for offering to look at the skin. The good news is that the DDR menu magically started working with no further changes on my part (it's now the next day and perhaps the application automatically restarted, pulling in the new copy of web.config?), the bad news is that I don't see an Attachments function on this blog window -- I see buttons for Bold, Italic, Underline, Quote, Code, and Submit. Even though the DDR menu now works, I'll try the Code button to see if I can paste in the ascx file which I had whittled down to just a few lines:
<%@ Control language="vb" AutoEventWireup="false" Explicit="True" Inherits="DotNetNuke.UI.Skins.Skin" %>
<%@ Register TagPrefix="dnn" TagName="NAV" Src="~/Admin/Skins/Nav.ascx" %>
<%@ Register TagPrefix="dnn" TagName="USER" Src="~/Admin/Skins/User.ascx" %>
<div id="menu" width="900" height="31"><dnn:NAV runat="server" ID="dnnNAVMain" ProviderName="DDRMenuNavigationProvider" IndicateChildren="False" ControlOrientation="Horizontal" CSSControl="NavMenu" /></div>
<div id="ContentPane" runat="server"></div>
<div id="ControlPanel" runat="server"></div>