It sounds like includes/languages/YOUR_TEMPLATE/english.php (where YOUR_TEMPLATE is the name of your custom template) was incorrectly edited.
To remove the text, just remove the portion between the single quotes. If you remove the entire definition, files that use it will display the constant FOOTER_TEXT_BODY.
If the information in the footer used to read something like
define('FOOTER_TEXT_BODY', 'Copyright © 2003-2006 <a href="http://www.zen-cart.com" target="_blank">Zen Cart</a>. Powered by <a href="http://www.zen-cart.com" target="_blank">Zen Cart</a>');
You should change it to
define('FOOTER_TEXT_BODY', '');
I changed the color of the single quotes to make it obvious that it's not a ".
Mary Ellen
I came; I saw; I Zenned
Taking over the world... one website at a time
Make sure brain is engaged before putting mouth in gear... or fingers to keyboard.
Holzheimer
Fan Odyssey