lhungil:
I'm going to "guess" you have a ".htaccess" file in the root of your website (or /images). Why? Because all 404 errors are going to Zen Cart's "file not found" page. Mistakes in a ".htaccess" can cause unintended side effects such as those your store is exhibiting. Please post the contents of any ".htaccess" file present in the root of your website (obscure any references to the Zen Cart "admin" folder if present).
This is the .htaccess on /images
# @copyright Copyright 2003-2010 Zen Cart Development Team
# @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
# @version $Id: .htaccess 16111 2010-04-29 22:39:02Z drbyte $
#
# This is used with Apache WebServers
#
# The following blocks direct HTTP requests to all filetypes in this directory recursively, except certain approved exceptions
# It also prevents the ability of any scripts to run. No type of script, be it PHP, PERL or whatever, can normally be executed if ExecCGI is disabled.
# Will also prevent people from seeing what is in the dir. and any sub-directories
#
# For this to work, you must include either 'All' or at least: 'Limit' and 'Indexes' parameters to the AllowOverride configuration in your apache/conf/httpd.conf file.
# Additionally, if you want the added protection offered by the OPTIONS directive below, you'll need to add 'Options' to the AllowOverride list, if 'All' is not specified.
# Example:
#<Directory "/usr/local/apache/htdocs">
# AllowOverride Limit Options Indexes
#</Directory>
###############################
# deny *everything*
<FilesMatch ".*">
Order Allow,Deny
Deny from all
</FilesMatch>
# but now allow just *certain* necessary files:
<FilesMatch ".*\.(jpe?g|JPE?G|gif|GIF|jpg|png|PNG|swf|SWF)$" >
Order Allow,Deny
Allow from all
</FilesMatch>
IndexIgnore */*
## NOTE: If you want even greater security to prevent hackers from running scripts in this folder, uncomment the following line (if your hosting company will allow you to use OPTIONS):
# OPTIONS -Indexes -ExecCGI
