Firefox 3.0

I updated to Firefox 3.0. Now every time I close Firefox and then open it back up I lose my bookmarks, the back button doesn’t work, and nothing is remembered on my computer (passwords, auto logs, etc). I have tried unloading and loading it again. I have gone on to options and made sure the correct items are check or unchecked whatever the case may be. Nothing seems to resolve the problem. Can anyone help?