I agree and disagree with autosave and here's why:
-Agree because nothing is worse than being on a roll and getting excited about a new sound or tune, only to have some freak accident and lose it.
-Disagree because if you are trying something, like for example, resetting the mixer and redoing a mix, but don't like it and then all the sudden have an issue like yours, you are SOL on that sound that was better before trying to redo the mix.
Here's my horror story:
The worst thing that ever happened to me was I deleted a song file and started over from scratch. I soon realized I wanted my song back because it had a cool vibe and bad ass snare I couldn't find again. Luckily, I made an mp3 before deleting the song file and had to play it by ear; literally. Got pretty damn close. Close enough to get back on track. Now I save after every few changes! I'm like a paranoid saver!!! And for good reason.