Info needed for displaying online users

[richever]

How does vb determine if a user is online?

My problem is that when a user creates a post, logs off and then another user or guest logs on and reads this post, the authoring user is displayed as still logged in. I checked the session table and the authoring user (which I logged out) does not have an entry.

So, where is the logged in status for a user pulled from?

Thanks.

Rich