· This morning, the debut of “Postman Pat” on HBO.· Tonight, the Redskins play the nike Shayne Graham Jersey Ravens in their last preseason game on CSN and WUSA.· “Children of Beslan” on HBO.· And a “Being Bobby Brown” marathon on Bravo.Children’s Series DebutPostman Pat. This animated British import follows a neighborhood mail carrier as he makes his rounds in a close-knit rural community (HBO at 8 a.m.).SportsTennis. Early-round coverage of the U.S. Open from New York (USA Network at 11 a.m. and 7 p.m. with a half-hour recap show at 12:35 a.m. on Channel 9).College Football. Oregon at Houston (ESPN2 at 7); Central Florida at South Carolina (ESPN, 7:30); Minnesota at Tulsa (ESPN2, 10:15).NFL Preseason Football. Washington at Baltimore (CSN and Channel 9 at 8).Prime-Time MovieShanghai Knights (2003). Jackie Chan Browns Shayne Graham Womens Youth Mens Kids Sale and Owen Wilson star in the comedy/action flick (Channel 7 at 8).NewsmagazinePrimetime reports on the aftermath of Hurricane Katrina, plus a segment on welders claiming that their job puts them at risk for Parkinson’s disease (Channel 7 at 10).Cable SpecialChildren of Beslan profiles the young survivors of last year’s three-day siege by rebel extremists at a Russian school, which left more than 350 people dead, half of them children (HBO at 8).Cable SeriesBeing nike Shayne Graham Jersey Browns Shayne Graham Womens Youth Mens Kids Sale Bobby Brown repeats the wacky reality series’s first four episodes (Bravo at 10).SeriesPrison Break (R). A rerun of Monday’s premiere of the drama series about a man who breaks into prison so he can break his brother out (Channel 5 at 8).Big Brother 6. Preempted by the Washington Redskins-Baltimore Ravens preseason football game, the elimination episode of the reality series airs at 2:35 a.m. on Channel 9.Late NightThe Tonight Show With Jay Leno (R). With Matt Damon and Tommy Lee (Channel 4, 11:35).Late Show With David Letterman. With Stephen Colbert and music by Black Eyed Peas (Channel 9, 11:35).–John MaynardThe TV Column will return.