Rachel Bilson and Hayden Christensen Are On

Rachel Bilson has denied reports she's split from fiance Hayden Christensen after she was photographed without her engagement ring.The couple, who met on the set of the 2006 movie "Jumper," became engaged in December.The pair has been dogged by rumors of a split in recent weeks and the former "The O.C." actress fueled speculation when she was recently spotted without her diamond band.But her