Eleven districts have sued Education Commissioner Robert Scott over his interpretation of a new law barring minimum grading policies, reports the Associated Press; a hearing was scheduled Monday in Austin. Some districts have had policies that if a student failed and earned a zero, his or her grade automatically was boosted to the minimum score. The districts, mainly in the Houston area, argue that not allowing students a grade below 50 allows room to improve and eventually get course credit. The districts also say the law should only apply to assignments…