I use Opera, but I noticed recently I started getting logged out constantly. Not sure why it wasn't happening earlier. Was reading a really long thread, and it happened when posting as well. But I noticed there was the "remember me" button in the log-back-in screen below the page's header login, and tried that. Now there hasn't been anymore prob. with that. But right after I fixed it, I have a more annoying problem. Will have to start another thread about that one.
After a quick grumble to Karlos I discovered that button in the top right and now I never get logged out unless I do so myself, saves a lot of frustration like you say when typing a long post only to find you've been logged out while typing it and it's gone forever... 
In my browser, when I got logged out typing a post, it didn't lose it on me. It went ahead with it when I logged in again. But you should always know better than to submit something you typed on the web, especially something long, without first copy/pasting it to an editor on your own system!
Since so many sites will lose everything on you if anything goes wrong, and there's so many things that can and often do.
Some peepoles tipe slowa than udders
And some just take a while to figure what they're trying to say, or are too perfectionistic and edit their post a bunch first.
