When we ask TP to 'remember me' when we log on, a cookie is used so that the forum software knows that.
The software explains this as "This is the time in seconds that a user must remain inactive before their login session expires. This setting also controls how long a user will remain on Who's Online after their last activity."
At various times the cookie has had different settings. At present it is 4 hours.
As citybythesea says, Internet Explorer may also cause some interesting side effects as it is quite buggy software and Microsoft keeps updating it and introducing new bugs. I think Internet Explorer causes more problems on my PC than any other software. Mozilla Firefox is much more robust as a browser, but I have become so used to Internet Explorer and its quirkyness over the years that I continue to use it for most things.
As far as I can see the things that may affect the areas in question are:
- whether you ask TP ro remember you
- whether you shut your browser down, or just TP
- time between visits in the course of a day
- whether you shut your PC down [ can't see what this would do, though]