Mac OS X 10.9.4
Java 8 Update 5
2.4 Ghz Intel Core 2 Duo
NVIDIA GeForce 320M 256 MB
If you generate a world with world type customized and set the dungeon count to a high number there is a chance that the dungeons will overlap.
When this happens there is a chance the chest(s) get destroyed dropping its loot.
How to reproduce:
Generate a world with world type customized and set the dungeon count to a high number. Look for two dungeons close to each other. There is a chance you will find a bunch of items on the floor.