I have come back from a family vacation looking forward to put my hands on this problem: I was shooting with my Nikon D600 camera and a dreadful message showed up (card err). I changed to a different card and had no problem with it for the rest of the trip.
The problematic card is a Kingston 32GB which contains some hundreds of RAW (.NEF) files. I have tried different programs so far without success: Lazesoft, ZAR, PhotoRec, testdisk. Windows sees the drive (e:) but doesn't allow to explore it. Testdisk shows a partition error message. Photorec, after 5 hours hasn't found anything.
This is really desperate, I can't imagine missing those photos. Ideas?