Same for thedeveloper, it crashes on close for me. I'm using windows vista home premium / service pack 2. I don't know if I'm supposed to report it because you already know about this bug.
Things I did:
1. Create a new project
2. Add Sprite (I saved the sprite as it is, I didn't draw anything on paint. But I can draw or paste images, it'll just be same in end.)
3. Save, then Exit -> *crash*
(It happens with capx and folder types. Same result.)
It did save the project though. So I reopened the project, removed the sprite, and save/exit. It still crashed. It didn't crash for me if I only used mouse, keyboard, or text. It only does it with the sprite.
EDIT: Forgot to mention I'm using 32bit.