I am having problems getting my D800 to use one card for NEF and the other for JPG, no matter what settings I change I get two shots one on each card but both in JPG, I have been through the manual and still cannot get it working correctly.
I've got a D600 but in the shooting menu there is an option "Role played by card in Slot 2" and underneath it an option "Image Quality"
Set the image quality to RAW + JPEG then set to Role played by option to your choice...
Should be in the same in the D800
nzswift, thanks mate, just finished the update for the D800 and then followed your info re the RAW + JPG, all now working as it should, my fault for changing some menu options.