Thanks for your advice. I solved the problem, thanks for the help. Apparently as you told me the problem is that the JBoss was making cache from the login. So i changed the jboss-service.xml to not make cache from it.
And it works. But not for my case, because the login module execute the logout before the login everytime the user attempt to enter again in the other browser.
Solution for my case:
Create a filter that manages the users online that are keeping in a set in the application scope. Use a session listener to remove the user from the set.
The solution must be clustered, so the application scope is not distributed.
Maybe i need to access the JBoss Cache from the JBoss to keep the set.
How to do that: I dont know, some advice? ehhe