you didn't perhaps click on the "save draft" option, eh? that's codeword for "throw everything that i've just typed out away"
most of the boxes on fhdc default to using dummy mode (i.e. automatically changing newlines to <br> and similar) if you have no HTML tags *and* no HTML entities in your post. if you have any HTML at all then the box is in pure HTML-mode.
personally i always start writing in dummy mode, add one little thing that pushes it into HTML mode (i.e. in this post it was the <br>, bare ampersands deliberate) and then I have to go back and add <p>'s and <br>'s where appropriate. *shrugs* seperate your paragraphs with a blank line and then the re-editing isn't that bad.