PPPoE Internet connected, But YAST cannot connect

I have PPPoE Internet connction. I have setup RP-PPPOE as Dialer on Opensuse 11.1

I can connect my Internet connection and can surf net via Firefox, but no other application can connect to net.

Pidgin, Filezilla, Yast to install anything, System Update Manager and all other application cannot connect to net. Only Firefox works.

I have also tested Firefox Network settings and it’s on No Proxy

Please help me how to setup this. I cannot install anything.


One more thing
I can surf net only one session of Firefox.
It means that I connect to net and than surf using Firefox. But if I restart Firefox than connection lost. And I again resetup the DNS related section and can surf the net again only via Firefox.

The problem is solved.
There is DNS problem.