Quick story: I almost lost this image to Flash Limbo when my file went corrupt on a system lock-up. This is where you click on the .fla, and Flash politely informs you that it is unable to open the file. Period. Gone for good. GAME OVER. Well, this time on a whim I tried swapping the file extension to .jpg, and then back to .fla. And when I tried to open it, it worked!—but only for a few moments until the file would crash. So, I published it as .swf to get the artwork out, and then re-imported the .swf into a new Flash file. It worked, image saved! So, it's worth a shot if you find yourself in a similar (horrible) situation.
I leave you with this thought: Wouldn't it be cool if you were inking a drawing on paper and it all of a sudden vanished (POP) from the universe? No, it wouldn't. This is what is fundamentally bad about computers. Your artwork doesn't exist anywhere outside of those 1s and 0s. Artist, beware.