Okay, once again, seems we need to clearly define what a "lie" is.
Obama claims he was not referring to Palin when he made the crack and that McCain is lying saying oh yes he was.
HOWEVER!!! When Obama said that, the crowd went nuts laughing and chanting "Palin". Did he correct them "Oh no that was not what I meant". NO he did not. He just smiled and went on with his speech.
SO, with "inference" we can conclude, he did indeed mean to refer to Palin.