[kde-linux] how to troubleshoot browser - http

[Robert]

Hello

All my browsers stopped working today: they cannot access any web site when 
I type http://a_asite.
I verified that my connection works using host -a  or ping.
I tried to go online with Konqueror and I get the same result: "Unknown 
Host. an error occured while loading http://www.google.com".

There is something wrong in a component between kde and the http connection.
Any idea of where to start to troubleshoot?

thanks
Laurie