[Lauren [is Lost]]

I was wondering what could have been going on on the island too...Jack said that 'Jeremy' had told him that bad things had happened on the island since he left, and that 'it was his fault'. So it is seemingly related to Jack somehow...hmm.
Good shout about John having to move the island also - would explain how/why he ended up back 'on land' as it were! Seems like a strong possibility.