The Dallas Mavericks are developing a knack for letting easy wins turn into tough ones. In their first game since needing overtime to salvage what was once a 20-point lead, the Mavericks needed double overtime to beat the Philadelphia 76ers 125-122 Wednesday night after letting a 15-point fourth-quarter lead slip away. "We keep shooting ourselves in the foot," said Antawn Jamison, who scored 23 points. "We have to understand the urgency of the situation. We have to fight and stay competitive ...