A federal judge on Wednesday refused to dismiss a lawsuit challenging Delaware's abandoned property collection system, raising questions about the constitutional validity of one of the state's largest revenue sources. Wednesday's ruling by U.S. District Judge Sue Robinson involves a lawsuit filed last year by packaging company Temple-Inland Inc., a subsidiary of Memphis-based International Paper that is incorporated in Delaware Temple argues among other things that Delaware's practice of estimating unclaimed property liability for years in which actual records are not available amounts to an unlawful taking of property and violates constitutional provisions regarding due process.