RELATED STORIES: Four property-rich Texas districts have filed a lawsuit challenging the constitutionality of the state's "Robin Hood" school finance law. The districts are among many property-wealthy Texas school systems that are required to share some of their local property-tax revenues with property-poor districts.(Houston Chronicle--free registation required)...Earlier, taxpayers in the Dallas and Highland Park, Texas, school districts filed a similar suit to challenge the law. (Dallas Morning News)