A problem experienced by many here is losing everything they have written into a post box if they move forward or back with their browser before posting. In other words, you start to author a post but then click "back" to check something. When you return, your text is gone, and you have to start over. This most commonly occurs with Internet Explorer.
Here's a very helpful explanation of what's going on from a post by rjackson
HTTP is a stateless protocol -- meaning, as you navigate from one page to the next, there is no mechanism to keep state. That's why things like cookies and sessions are needed, to keep track of you as you move about the site.
So when you click on a link, communication is sent to the server that requests the page you want, and the server processes and returns the page to you. That's it; no more is transmitted. When you type a post, it's stored locally in memory until you hit the submit button. Then it is transmitted to the server via an HTTP POST request. If you type a post, however long, and then navigate to a different page, everything you typed is lost once the new page loads because you did not submit it.
Basically, there is no way for the site to "hold" your post, as you type, if you click on a link and go somewhere else.
Most browsers have the nice feature of storing what you typed in memory, so that if you do navigate away, your content is preserved when you go back through your history.
I, too, would recommend upgrading to a modern browser, such as Firefox or Opera. Usually what I do, if I need to look something up while I am typing a post, is open a new tab and do it there. That way what I'm writing isn't lost; it's saved in the first tab.