New Falluja Fighting

Reuters reports new fighting in Falluja, despite the truce announced yesterday. However, the story contained this interesting bit:

"The fighting erupted hours after U.S. Defense Secretary Donald Rumsfeld said the truce in the battered city of 300,000 people west of Baghdad would not hold indefinitely. He said days of talks involving Iraqi and Sunni Muslim leaders, Falluja officials and representatives of the U.S. governing authority in the city did not include Iraqi insurgents who have been confronting U.S. troops."

So...we are negotiation a truce with people who aren't fighting us? And it won't work? What, precisely, are we doing in Falluja? Is this an attempt to win over the non-militant Sunni leadership, gaining actual allies against the insurgents?