To avoid a new topic, one more forum request is to have typing a post count as "activity". Earlier today I was trying to write a post, but by the time I actually hit "post", I was logged out. Ideally, allowed idle time before it logs you out should be increased, but detecting when I'm busy writing would help resolve this just as well. Sure, there probably aren't many who sometimes re-write a post 3 times before submitting, but there are enough who may need to look something up or in some other way get distracted, so that they later are typing away yet still get timed out.
I won't make a big deal about it, but please consider removing CAPTCHA for every post. Solving CAPTCHA more than once is useless- passing the first one means I am either human or a bot that beats CAPTCHA anyways. Of course, if you have tried a more lenient policy and it failed, I can understand the current situation.