Reporting from Washington Troops serving in Afghanistan were advised never to touch the Koran, never to place anything on top of one, and to keep it off the floor and out of bathrooms. They were even told never to "talk badly" about it. But the do's and don'ts said nothing about burning the Muslim holy book, which is what happened last month as a cache of Korans was incinerated at Bagram air base, setting off riots across the country that killed more than 30 people and provoked attacks on U.S.