Problems

DDDnD3D, actually that's a problem with the "cookies" placed in your browser, which expire after an hour (if you log in at the top of the page) or two hours (if you log in at the bottom.  You can set them for "all day" and forever" but I've never done that myself, so I'm not sure how it works.

My advice, if you think you've been at the forum for over an hour, would be to "select" and "copy" before you post a message.  If you get the error message, all is not lost, though, you just have to hit the back button to get back to your original post before you sent it, it should still be there.