This isn’t the first time it’s happened to me: I type a message and after some one or two hundred words, while editing, I click at the wrong place and pressing backspace doesn’t erase the text but takes me back a page, as the focus is now on the window, not the edit – well, you get the idea.
Do you think you could introduce either an auto-save feature (remember what Al says: “Save early, save often!” ;o) or a security yes-no-query if the page is exited without Posting?