A birthday call from Paris Hilton to Nicole Richie ended the SIMPLE LIFE star's long-running feud. The socialites, now best friends again, fell out under mysterious circumstances in 2005. Insiders claim the friendship turned sour when Richie screened Hilton's ONE NIGHT IN PARIS sex tape at a party. Both have refused to reveal the details of their split, but Hilton has come forward with information about the phonecall she made to end the hostility last September (06). She says, "It was Nicole's birthday and I really missed her and I just decided to pick up the phone and call her." Speaking to US news show EXTRA, Richie adds, "We just got together that night and it was like there was never anything that happened. "It was weird, like we had seen each other yesterday."