[spoiler= another thought]
was thinking about the earlier episode with Desmond jumping in and out of time not knowing his "constant" he was affected by magnetic matter in season 2 finale with the hatch blowing up.
assuming that leaving the island affected some type of "time travel" constant thus why he was not in the same place at one time. ....makes more sense now after seeing the Dharma vid.
what i dont get is why isnt Walt affected in any way. He seems to be doing fine after getting off the island. [/spoiler]