Session length

Hey,

I just installed your plugin and it shows that all user sessions expire in 12 months which is correct because i have another plugin that it supposed to keep users logged in for a year. But for some reason, i see that a user logs in many times during the day, and then the next day, and the next day. So while his session is supposed to last for 12 months and your plugin shows that indeed it expires in 12 months, looks like the user has to manually log in every time he opens the page because his session expires every time he closes the browser. Any insight why this is happening? I suppose your plugin shows correct expiration date (in 12 months) but what could be the reason why users′ sessions don′t last 12 months and they have to log in again and again?