Where did you buy the cards? There are a LOT of fake cards around. Test your cards with software h2testw software. Google it, it's free.
Edit: Marcel beat me to it
It should be valid to do what he is doing. When I was first trying raw, I shot raw+jpg and experimented with letting the camera mix them together or put the jpg on card 2.I am not sure there is a problem with your cards or your camera.. i could be wrong but try this...
You said you have chosen the option for file format as 'RAW + JPG'
And you have chosen the function of card 2 to save only JPG files..
This may be confusing your system as one option tells the camera to create a RAW & a JPG while copying & another instruction tells the camera to save a JPG file to card 2...
To cut it short, choose your file format as RAW & leave the card settings as it is ie. Card 2 for saving JPGs
see if that works
ok test result for the 16GB card :-
However, one thing still doesnt explain is how can the card (be in fake or not) can be read in slot 1, but cannot be read in slot 2... This doenst make any sense at all . Is Nikon have some kind of anti-piracy agent build in the engine? if it does, how come it cannot read the 8GB card (it already proof genuine by the registration in sandisk website).
If the slot is faulty, why can it still read and write when i inserted the toshiba card.
This seem to puzzle me and haunted me even in my sleep. At first, maybe the slot/body is faulty. but then after i try with toshiba, it's ok. So let alone the cards are faulty but then, card no 2 (8GB ) is genuine, how can it still be problem.
I just tried this. (if I understood correctly). If I'm set only to RAW only and the role of slot 2 is jpg, it gives me a second copy of the raw on card 2, no jpg. So it seems to behave as if it were set to backup for card 2 role. I think if you want raw on card 1 and jpg on card 2, you must also select raw+jpg.I am not sure there is a problem with your cards or your camera.. i could be wrong but try this...
You said you have chosen the option for file format as 'RAW + JPG'
And you have chosen the function of card 2 to save only JPG files..
This may be confusing your system as one option tells the camera to create a RAW & a JPG while copying & another instruction tells the camera to save a JPG file to card 2...
To cut it short, choose your file format as RAW & leave the card settings as it is ie. Card 2 for saving JPGs
see if that works
I'm getting confused. Your 16gb card is definitely suspect. But does your 8gb sandisk and 8gb toshiba both work no matter which slot they are in? If the 16gb is the only problem, it does not trouble me too much that it works in one slot and not the other. Bad memory can be touchy, it could be unstable and a very slight difference in power supply levels might decide if it works or not. But I still worry about your camera, the camera could also be marginal causing one slot to be more reliable than other. If the two 8gb cards work, that is good, but I would still want to test both slots with at least two new 16gb cards before your warranty is gone. I would want to test the camera with many different cards after all this trouble. Is your camera shop local? Maybe they can help you out by trying some of their cards.
I just tried this. (if I understood correctly). If I'm set only to RAW only and the role of slot 2 is jpg, it gives me a second copy of the raw on card 2, no jpg. So it seems to behave as if it were set to backup for card 2 role. I think if you want raw on card 1 and jpg on card 2, you must also select raw+jpg.
Have you tried a full reset of the camera?
Have you tried the reset where you hold down the QUAL + Exposure Compensation buttons (both buttons have a greed dot on them) together for 2 seconds??