Yup, problems with Tiscali, seem a few other examples.
Not confirmed what server(s) are causing the problems, but Libertysurf's is and Tiscali mail does seem to go through there.
http://www.senderbase.org/search?sea...g=213.36.80.91
Only way to confirm is to find out what server her mail is going through, which should be stated in the bounce message, otherwise you can find it by asking her to send a mail to a non-ntl address and checking the headers.