Missing Images in a PDF Report
Images that appear in reports rendered as HTML are missing in reports rendered as PDF. The embedded GIF, JPG, and BMP images do not appear. Only the borders of the missing images appear.
The "HTTP Keep Alives" option is not enabled in IIS webserver
If you use Microsoft Internet Information Services (IIS), go to the properties sheet of the Web site and ensure that the Enable the "HTTP Keep Alives" option is selected.
Ensure that the virtual directory where the images are stored has anonymous access enabled. Open IIS and open the properties sheet for the virtual directory for your images. Select the Anonymous Access check box.