There are two ways to deal with it that I know of. You can either use save as, to save your work incrementally. That way, when you hit the bug, you'll only lose the work you did after the last time you did save as. You can also save frequently and then copy the file to another folder. More complicated, and it does virtually the same thing. The only difference is that you'll only have two files, the original and the copied file (assuming you keep copying over the files as you go).