Just noticed that I was no longer logged in in IE9 after a period of doing nothing, but having the website open? Did something change? I don't store cookies or history or whatever, but this never happened before.
Firstly, we did make a change to cookies about a week ago where everyone was logged out. I started a thread about it apologizing. :) So if you've had your browser open for over a week, then that's the reason why.
Secondly, to prevent against spam, you cannot submit any forms after a few hours of inactivity on the site. That's probably what you're referring to.