It has been brought to my attention and I have done this a few times myself...
When typing long posts, it is likely that you will get timed out for inactivity and lose everything that you jsut speant all that time writing.
WORKAROUND!!
Before you hit the submit button, highlight the entire tect and hit <cntrl> <C> (copy) and make a copy to your clipboard, or even better to a notepad. Then submit your post. If you are still logged in your post will be entered fine. If youve been logged out, you can go back and reopen the message/mail etc that you were working on and all you have to do is <cntrl> <V> (paste) the text back into the window.
Saves the trouble of rewriting the whole post again.