USERSETTNGS not clear on Login view (user and password)

Friends,

I have one view LOGIN, and this view uses Settings components to link table USER. It´s de start view.

Others view´s only show after the user insert your credentials (don´t worry…informations not realy)

Until last week it was normal, but now the variable USERSETTINGS() do not clear on leave application.

I don´t use USERMAIL() ou other to acess control.

Important: the APP use only on Desktop View.

I think what de problem is Cookies…somebody to help?