I've only been using this for less than a day, but I am already getting very annoyed at the fact that waiting a short time before clicking a link (including following a tag or submitting a post/comment) means I get a timeout and redirect to /deadlink. So, I have to hit back, copy my comment/post to the clipboard, refresh the main URL, paste the comment/post, then click submit.
All the important data should be stored and signed on the client so that it can be resent whenever needed instead of server-side timeouts. Of course, this is theoretically prone to replay attacks, so it should only be done for cases where the client could meaningfully intend, or the server could easily ignore, a replay, e.g. following a tag or accidentally making a post/comment twice.
1. Huge spike of users from reddit (you). 2. Server migration due to huge spike due to reddit (still you) ;) This rarely happens when we don't have 1000x the normal traffic.
I have found that if you take a long time to post, it'll timeout on you. I discovered this much to my chagrin after spending half an hour making a comment. To rectify this, I highlight and copy everything I just wrote right before hitting the "comment" button, in case of a time out. It's only happened to me once, but better safe than sorry. One of the things you'll notice about this site is that mk is constantly working on it and every time there's a change or a fix, he makes a post about it. He's very open as to what he is doing and why. Additionally, if you ever have any issues, create a post and tag it #bugski so mk, thenewgreen and everyone else who works on this site can see it. You'll be surprised to find that they're very quick to not only addressing issues, but rectifying them as well.
There are features in place to reduce the risk of you losing your comment. I still don't rely on it, but a lot of the time if it times out, you hit back, and you open the reply box (if it's not already open), it'll still be there. Magic.
I haven't encountered that problem today or any other day that I've used the site. The servers have been doing funny things today, so I'm assuming that your problem wouldn't happen with normal usage.
I've been getting a lot of these too, but I would imagine that has something to do with the increased volume of traffic to this site. Alexa.com wouldn't give me historical access data, but there was this: http://www.alexa.com/siteinfo/https%3A%2F%2Fhubski.com Check out towards the bottom the upstream sites - that indicates a lot of Reddit users have been hitting this place (that's how I found it, too) and are probably putting more load on the Hubski servers than usual.