Erro ao tentar instalar plugins no eclipse indigo 3.7

Colegas,
estou a muito tempo tentando instalar o plugin do google webtool kit no eclipise indigo 3.7 mas quando chega aos 48% da sempre a mensagem abaixo.
Poderiam me ajudar por favor?

An error occurred while collecting items to be installed session context was:(profile=epp.package.jee, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=). Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.core_1.2.0.r37x201112290923.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.core.databinding_1.2.0.r37x201112290923.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.core.databinding.xml_1.2.0.r37x201112291009.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/features/org.eclipse.wb.core.feature_1.2.0.r37x201112290923.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.core.lib_1.2.0.r37x201112290923.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.core.xml_1.2.0.r37x201112291009.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/features/org.eclipse.wb.core.xml.feature_1.2.0.r37x201112291009.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.css_1.2.0.r37x201112290951.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/features/org.eclipse.wb.css.feature_1.2.0.r37x201112290951.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.jdt.fragment_1.2.0.r37x201112290923.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.os_1.2.0.r37x201112290923.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.os.linux_1.2.0.r37x201112290923.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.runtime_1.2.0.r37x201112290923.jar dl.google.com Unknown Host: http://dl.google.com/eclipse/plugin/3.7/plugins/org.eclipse.wb.runtime.lib_1.2.0.r37x201112290923.jar dl.google.com