tag in MasterPage

I have an image tag on a MasterPage. The image tag shows me the image in Design view! However, when I debug the web site in VS 2005 the image box displays the red X to indicate that it cannot find the image. What gives??

  <tr>
<td><asp:Image ID="Image1" runat="server" ImageUrl="~/Images/wtf2.gif" /></td>
</tr>  ...