Aperture RAW question

Hi there,

When ever I import a RAW image into Aperture 3.4.3 from my Nikon D7000 - the image preview looks quite like what I get on the back of my camera on the LCD.

I am aware, that these previews are temporary JPEGs that are created by the camera and embedded in the RAW file, and not the RAW image it self.

However - once  importing is finished the image changes remarkably - the contrast is dramatically enhanced and my portraits (on black background) turn completely dark.

I have cancelled the import adjustments in the import menu and I really don't see where this auto adjustment takes place. I think that the changes are due to some kind of auto enhancement - but I really cant find out where it takes place. I believe the program hasn't always done so - so where the **** did I change something??

Is it because Aperture is using the camera previews? And why should these differ so much from the actual file?

Kind regards

Jacob