Oh well, I uderstand your feeling. What happened? Did the game hang the computer (it's normal
save, save, save,...) or did the computer disintegrate because of overaging? A few notes.
1. The Heart of the Dragon is a "fixed" treasure. You will find it again at the same place. You haven't lost it.
2. The centaurs can drop not only assassin robes but also Wizard Blades or Main Gauches+2. Always check the items dropped by centaurs!