I believe the problem is that adobe doesn't read the proprietary settings nikon uses, whether it be lens corrections, effects or any other in camera settings.
Jpegs are fine because the settings are baked in sorta speak.
With photoshop elements your probably going to have to use Filter>Correct Camera Distortion in the pse 11 editor to fix the the distortion your seeing.
Also, you might try opening the files in Nikon View NX 2 to see how the raw files look.
Do as R.Kelly suggested but you may also want to try the software that might have come with your Nikon Camera. You never know Nikon might know things that Adobe may not be up to scratch because of the time lag of software updates and the release of the new camera.