Problem using Webclip portlet

Hi,
I want to use the portlet
Portlet-> Internet - Tools → Webclip
But when I specify the URL and try to load the page it gives me following error message.
An error occurred loading [URL=“http://www.yahoo.com/”]http://www.yahoo.com/[/URL]
java.net.UnknownHostException: www.yahoo.com
www.yahoo.com
How this can be resolved?