Users that logIn with facebook/JFBConnect can get kicked out of their sessions.
This unstable connection happens after 4, 5 days of frequent use.
We had this issue with Chrome, Firefox and IE with different accounts.
Can you explain a bit more about how you're testing and what you're seeing?
* Does this only happen when users authenticate with Facebook, or when they authenticate using Joomla as well?
* Can you check the URL bar and make sure the domain or scheme isn't changing. For instance, if they are logging in at http://site.com, make sure the URL never updates to https://site.com or http://www.site.com. Any changes in the domain or scheme can cause the session to be lost.
* When you say 4-5 days of frequent use, what do you mean? The user is logged into your site for 5 days straight and suddenly they are logged out?
Any more information you can provide on how you are testing or any other variables we should know about would be very helpful.