Please create or edit a .htaccess file in
http://www.ibphoenix.com/downloads/ directory.
Contents of that directory fails to work in Firefox browser.

.htaccess file have following two lines:
AddType application/pdf .pdf
AddType application/zip .zip


Also, can modify following <Directory> directive in 'http.conf' file
on server:

AllowOverride None
# change above line to
AllowOverride All

Restart apache after above changes.