Remove the image assist icon from Drupal textareas

This small theme override will allow you to select which Drupal textareas the image assist icon will appear on

/**
 * Theme for adding an image link underneath textareas
 */
function phptemplate_img_assist_textarea_link($element, $link) {
  if ($element['#id']=='edit-body'){
    return theme_img_assist_textarea_link($element, $link);
  }
}

The above code will limit the icon to appearing on only the node edit body fields, you can add more ids as required