You are probably using Apache and the default Apache icons alias is overriding your ConfTool icons folder.
You can check this by entering the URL of the icons folder in your browser, e.g.,
http://www.your-site.edu/icons/When the Apache icons are shown after that, you found the cause of your problem.
If this is the case, please look for:
Alias /icons/ "/usr/share/apache2/icons/"... in your Apache configuration and insert a comment sign ("#") before it.
Then restart the daemon.
You can find this definition often in the file called:
/etc/apache2/mods-available/alias.conf