Has nothing to do with admin settings, which are already configured to show CSS buttons.
Please see THIS thread which explains the issue: http://www.zen-cart.com/showthread.php?50146-Using-CSS-Buttons-still-seeing-quot-Update-cart-quot-gif
THIS mod fixes things, 1st one is original, shows image, 2nd one is new, shows CSS button:
//$buttonUpdate = ((SHOW_SHOPPING_CART_UPDATE == 1 or SHOW_SHOPPING_CART_UPDATE == 3) ? zen_image_submit(ICON_IMAGE_UPDATE, ICON_UPDATE_ALT) : '') . zen_draw_hidden_field('products_id[]', $products[$i]['id']);
$buttonUpdate = ((SHOW_SHOPPING_CART_UPDATE == 1 or SHOW_SHOPPING_CART_UPDATE == 3) ? zen_image_submit(BUTTON_IMAGE_CHECKOUT, BUTTON_UPDATE_ALT2) : '') . zen_draw_hidden_field('products_id[]', $products[$i]['id']);
Now to find/fix the alt text for the update button...hopefully not too long, plus do some additional experimenting...
Thank you, Tom