Why do I have to keep logging in?

When I use this site and log in I seem to keep getting booted or something. I’ll be reading threads or viewing stuff from links posted by other members and when I try to do something like make a post it tells me to log in. But I was already logged in. Is the site on some kind of timer? What’s going on?

Send a PM to Goofster. He will be able to tell you more, I hope. This is above my knowledge of the site.