I am finding this especially irritating when you are writing a reply on a thread and within minutes, and seriously, its no more than 4 or 5 when I am typing...as I go to submit reply I find I have been logged out. My response has been totally deleted. I understand the website is trying to push off the ones just sitting and doing nothing, but if you have logged in and are replying and in a reply box which I know has HTML to post it anyway or some such, why are you logged out before you can click submit??? And even if so, why is your whole writing deleted? Because I know you can set the page options to just say "Session timed out" or something but your words are still their so you can copy and paste or save them or something. This is very frustrating. I've gone from being logged in for almost a week by clicking remember me, to just logging in a few minutes and trying to answer something but not having clicked the box and being kicked off and losing everything I've typed.
And just for the record, I have all cookies accepted on my computer, so that's not a problem of something not being recognized after some minutes.