Jessica Simpson Not all 'Smiles'

Jessica Simpson has been a huge supporter of 'Operation Smile' for 10 years but oddly enough she was a no-show at the Operation Smile benefit the other night, which really pissed off the charity.

According to the 'New York Post,' Simpson stopped doing charity work for them after her very public visit to Africa last year and after her split from former hubby Nick Lachey.

"She's turned her back on them," a source said. "She got a lot of good publicity from the charity but refused to let pictures of her be in the commemorative book and hasn't done anything with them in a year."

So was she a no-show or did she have prior engagements? A rep for Simpson said she was in Germany being honored at the UNESCO Gala to Benefit Children in Need, "partly for her work with Operation Smile. Jess was one of four honorees for her philanthropic work. She sang two songs, and the event raised about $3 million to build schools all over the world."