The Bush administration has announced it will delay the virtual US-Mexico border fence for another three years. The virtual-barrier south of Tucson, Arizona includes tower-mounted sensors and surveillance. At a hearing yesterday, officials from the Department of Homeland Security described mounting technical problems, including issues with software provided by the defense contractor Boeing. The company was paid $20.6 million for the project in December. The Department of Homeland Security will give Boeing an additional $65 million to replace their software.