This happens to me on these forums all the time. I usually keep a couple of pages open in my browser to check for new posts on the topic of interest. When I want to reply I type in my response and hit "submit" and it always says "my token has expired" or some such nonsense. I try to reload, still nothing, try logging out and logging in, still nothing. It usually takes me completely closing that window down and re opening the forums and hunting for the topic before I can actually post a reply, so aggravating, this is the only forums I have problems like this in and I haven't found a decent solution.

Also it seems that checking the "remember me" box next to the login is futile, I am usually logged out after a few hours whether I like it or not.

 

Sounds to me like you have some sort of program running on your end that's doing it, none of what you describe is a naturally occurring instance of any web browser.

Possibly an effect of your anti virus software. Or your on a network not of your control, ie: University, public anything network, library etc...