Look around the packed terminals at Tampa International Airport and you'd think everybody was on a warm-weather holiday. Not so. Transportation Security Administration officers at the airport got word last week that routine vacations were canceled through mid-April. Why? To make long, slow lines at security screening lines move faster. On March 25 and 26, early morning travelers flying Southwest, Spirit and Midwest spent an average of 30 minutes in line to get through TSA checkpoints. It was just as bad for US Airways and American fliers on the 26th. Wait times dropped back under 20 minutes once the TSA shifted around personnel and banned vacations for all but "exceptional'' situations, like weddings, said Gary Milano, the TSA's security director for the airport.