Trey Alessio had just settled into his seat in the press box Friday night when one of his Iowa Cubs colleagues came up and razzed him. Whoa.'' Alessio, a 21-year-old college student and media relations intern for the Triple-A Cubs, was the man who stopped and started Principal Park's three clocks - one by each dugout and another in right field - as full enforcement of professional baseball's new pace-of-play rules began. The first violation here occurred when the Oklahoma City Dodgers' Matt Carson stepped out of the batter's box after the clock had struck zero at the start of the sixth inning. Home-plate umpire Chris Gonzalez called timeout, pointed at Carson and then turned to the press box and signaled a 0-1 count.