Skinned UserControl Image Display Issues

I have a themed/skinned user control that is not resolving the skinned images correctly.  Fiddler shows that I'm getting a 404 on the images, however, they are actually there.  The only problem is that there is a red x transparently over the top of them.
My user control markup is:
<asp:Image ID="imgTitleEdgeLeft" SkinID="Common_Title_Edge_Left" runat="server" /> <asp:Panel ID="pnlTitleContent" SkinID="Common_Title_Content" runat="server" /> <asp:Image ID="imgTitleEdgeRight" SkinID="Common_Title_Edge_Right" runat="server" />
My user control code-behind is:
Namespace Controls Partial Public Class Title Inherits System.Web.UI.UserControl Private m_text As String = String.Empty Private m_width As String = String.Empty Public Prop ...