My LOST theories:
Black Rock: - How did the ship get located in the middle of the jungle? I think that this ship was just navigating somewhere on the ocean and suddenly the island moved and got placed where on that instance the Black Rock was.
Polar bear: - What are they doing on the island? They got trained on The Hydra to experiment the effects of moving the Frozen wheel. That explains the found skeleton of a Polar bear in Tunisia in the Sahara Desert... Same place where Ben landed when he moved the Frozen wheel.
Drug smugglers' plane - How did it ended crashing on the island? A Beechcraft 18 has a range of 850 miles/1400 kilometers. The distance from Nigeria to Fiji is 11,000 miles/18000 km. We know that the plane had a map of the Sahara Desert region, same place Ben got moved to when he moved the island. So the smuggler's plane was passing on that specific place in the Sahara Desert and got suddenly moved in space and time to the island. This explains why the place is seen by Locke just after the island was moved.