fyi, I've disabled the shoutbox for now - seems there's a lot of people that have got trouble keeping logged in, and I experienced problems myself as well. Seeing that the shoutbox is the last thing that was added, and because it seems to be rather heavy on the systems (at least, I think it is), I've disabled it for now - if it doesn't bring improvement, I'll turn it back on.
If it does turn out to be the cause, we'll have to switch to a more lightweight shoutbox solution, which won't offer as much features, but which'll be lighter on the systems.
Also, host.