Some unexplained things on Lost

What is the oddest thing that has happened on Lost that you have yet to see an explanation for? For me, I will say it is the "moving" of the island. It will be interesting to see how this gets explained....I am also curious as to how been was able to get Locke's dad on the island....
(P.S.: I love watching the Lost DVD only because they have a lot of behind the scenes stuff, and provides a little more depth. I hate watching when a scene comes up, and leaves much to be desired. Half the time, I'll grab my laptop real quick and start looking for answers on Lost Forums.）