Error after submitting request

Hi,
I am working on evaluating soapUI 4.5.1
I created new project and added the wsdl : http://www.webservicex.com/CurrencyConvertor.asmx?wsdl given on this site under section working with WSDLs. When I double click the request and fill up the parameter values and submit the request, I get an error : Thu Apr 18 14:05:45 IST 2013:ERROR:java.net.UnknownHostException: http://www.webservicex.com

Please help