Awh.. I'm so sorry to hear that.
That has happened several times to me as well.
I think that it's more or less how your computer reacts with a Flash player.
I would definitely recommend downloading the file to save it as a back-up instead of just double saving it using the quick save.
I worked so hard on it....TT.TT I'm really devastated, I saved my drawing twice in each folder to have extra protection. I come back and click quick load only to find out that all of them have been cleared and say empty...I am extremely upset..