Arnett pays a stiff price for his Baghdad boo-booTuesday, April 1, 2003By MELANIE McFARLANDSEATTLE POST-INTELLIGENCER TELEVISION CRITICHaving spent half of last week in the throes of fever and flu-induced headaches, returning to physical health and unhealthy levels of cable news absorption felt downright refreshing.Then came Monday's news about NBC and National Geographic Explorer firing Peter Arnett after backing him on Sunday, and my head started throbbing again.Arnett, who made his TV career covering the Gulf War for CNN, has had his share of journalistic boo-boos. In 1998, CNN fired him after he alleged in a documentary that U.S. commandos used...