Jennifer Aniston collapsed on the set of her next film, The Break Up las week. As more rumours regarding the star's former husband, Brad Pitt, and Angelina Jolie unfold, it looks like it has all finally taken its toll on the star. Although it was reported that Aniston suffered from heat stroke, insiders on the set say they feel it's a little more complex. "She's been walking around with a sad look on her face and has not been her usual self." Aniston herself is now having to deny rumours regarding her relationship with co-star Vince Vaughn. Representatives for the two have made statements that they are just friends. "She has talked about how she is not sleeping well, although she has been trying to be as brave as possible," added the source. | 
