After a WiFi session this morning the hosts chest with many items inside (iPad 2 iOS 6) disappeared after playing with the client (iPhone 4S iOS 6). I believe the client accessed the chest during gameplay and 'Copied and saved' when leaving. The items were not in the clients saved world.

Footnote: the clients saved world did not copy completely, some parts of the structures created by the host originally were generated as the world was when it was originally generated.