Nex 6 - Raw files - odd vignetting

Apple Aperture doesn't yet support Nex 6 raw files, so I thought i'd be clever and convert them to dng files using Adobe's DNG convertor. On opening them up in Aperture I found that the images are wider and vignettes at all four corners. So it would seem that the image is cropped a little bit.

This is definitely the case at the wide end of the new 16-50 zoom but not had a chance to test it with any other lenses. Anyone else seen this?