SAP POrtal application calling different r/3 system.

Hi Experts,

We  are using the Webdynpro abap applications in the Portal system. While accessing the application one pop-up window is displaying and asking for the user name and password and system showing xxx200 client instead of calling xxx400 client .

We have checked the System objects and SSO certificate also .

Still system connecting to Different R/3 system .Any body please help me why system still pointing to 200 client instead of 400 client.

SSO and System objects are connected 400 client only . 

Thanks & Regards

V.Punna.