Power Adapter Problem

[xantabulon]

I have a macbook, and when I plug in my power adapter with the two prongs/the "duck head", my battery does not always charge. I have to wiggle the adapter around and if it gets in the right spot it starts working. When I replace the duck head with the extension cord with the three prongs, though, it always works. Is this a problem with the duck head/do I need a new one?
Thanks

 

[BlueRevolution]

Take it to an Apple store. The power adapters are known to be shoddy and from what I've heard are usually replaced without question.

Also... "duck head"?