Hayden Panettiere can’t stand working on the same set with ex-boyfriend and Heroes co-star Milo Ventimiglia. According to reports, the 19-year-old actress is making things difficult for her 31-year-old former flame and the rest of the cast. A source tells OK! magazine, “She refuses to be on the set at the same time as him.” “She is making it difficult for everyone involved.” The couple finished their one-year relationship in February.