Hey. Thanks a lot for help. Feedback panel is shown now and sign out link appears when it should. But firefox still doesn't want to save and insert values for username/password fields. Usually, firefox asks to save login/password when form is submitted, but when form is submitted from modal window with ajax button, firefox doesn't ask anything. Also, usually firefox provides some variants of text that fits this type of input field. But this time for username input field it provides any information or some other information, but not that was typed earlier.
Also, I've got another question. How could I make modal window to fit to his content. I'm using setUseInitialHeight( false ), so height of modal window fits height of content, but width is still to large. Best regards, Alexander.