Customise Mollom status messages
If you look in the settings.php for your site, there should be a template for overriding strings in the interface (anything in the t() function).

You would add something like this to the settings.php file:

$conf['locale_custom_strings_en'][''] = array(
  'Old string'      =&gt; 'New string',
);


I haven't used it, but there's a module that makes this easier: String overrides.