Squidguard error page external redirect - no images

  • While I've read a few threads on this topic, I can't seem to find the answer I need.  I have squidguard redirecting blacklisted sites to an external webserver with a very basic error page (some text and a single image).  The text shows just fine but the image does not come through.  If I navigate to the error page directly it renders with no problems.  What is going on?