ssrs external image from ashx

Question

I'm trying to get a dynamic image loaded into SSRS 2005 from a handler. The handler works fine, when I set an asp:image src to it, it works as expected. When I add an image to an SSRS 2005 report and set the value explicitly in the value it shows the image in the designer. This is a local report being displayed in a ReportViewer control. When the site is run (via localhost) the image src is empty.