Extended Permission on Multisite Problem

Hey!

I Have Multisite Installation running with Ultimate Facebook plugin.

I have a user, with her own blog, with mapped domain.and she wants to use the facebook auto-posting feature.

On the autopost section there are no options in the selectbox "of user ...".

When she tries to grant extended permissions she gets this "loading blue lines"

"Use New FB User" button doesnot respond.
and
"Refresh User access token" yields this error:
"API Error Code: 191
API Error Description: The specified URL is not owned by the application
Error Message: Invalid redirect_uri: ?Given URL is not allowed by the Application configuration.?"

How to solve this?

Thanks,

Koff