DB sessions randomly logging users out

[eluser]WanWizard[/eluser]
Every session solution uses a cookie, to store the session_id client-side. This is how a request is matched to a server-side session. Sessions don't function without the cookie.

Next to ajax calls you can also loose the session if you have multiple concurrent calls to the application. This can happen if for example you have a missing image, that is being rewritten to index.php.