<p>I have a .asp application where image files (.PDF) are stored in a directory (fed by a copier/scanner). The created file names are stored in a database table.  When a query is launched from  the web page a link to the file is created. When clicked the image should be displayed.
This functionality works 100% in Internet Explorer. No such luck in Firefox (and I have some Firefox users). The created hyperlink looks like this <code>file://Server/Scanner/XYZ.pdf</code></p>

<p>The Firefox helps suggest the reason is this:  </p>

<blockquote>
  <p>Links to local or network pages do not work. As a security precaution, Firefox forbids sites on the Internet to link to files that are stored in your local computing environment. These files may include files on your computer, mapped network drives, and UNC network paths</p>
</blockquote>

<p>None of the suggestions for a workaround seem to work (or I am not understanding the steps to create the image display) 
Any Suggestions?</p>

shouldn't you really store the pages in your application directory and reference them this way.
http://SITENAME/Server/scanner/XYZ.pdf
.
We do something similar with files stored all in one directory and just store the file name. we then create the link using the known folder name and append the file name. this works quite well.
Finally firefox is a lot more anal about the directions of the slashes in file names as well. Make sure they are all '/' rather than '\'.
Hope this helps.