user activity plugin is not showing new login

We are launching a site upgrade soon (single site not multi) and our main need for this plugin is to track when users logon and logoff. I installed the plugin and logged in as the same user (theresa-curriculum) on two different browsers but the plugin only shows one login in the admin. How does the plugin define a separate instance of a login?

In addition, we would like to track how long they stay logged in, can this plugin do that or can you suggest another one of your plugins that might suit our needs? Additional wants are to track user activity like pages visited and certain click events.

thanks for your help
if possible please cc tnewman@channelone.com on your response.