Most themes also contain files to be used as ringtones/sms alerts etc, so in order to avoid the new ringtones being applied, you will have to modify the theme xml file, and remove the references to the new files; that way the old ringtones will stay put. For more info, check out http://my-symbian.com/uiq/faq/showquestion.php?fldAuto=7&faq=2