I am running the latest firmware: 1.03

Yep, firmware should fix it.

http://support.nikonusa.com/app/answers/detail/a_id/17542/session/L3RpbWUvMTMyMzg4ODUwMS9zaWQvQ2drdU1BTGs%3D

Download the firmware update. It was doing it with my 16 gig Sandisk extreme 3 cards but the firmware upgrade fixed that...

I have filed a problem report with Nikon, but 72 hours later, no reply. Here is the issue as I described it to Nikon:

Repeated Multiple "Card Err" on D7000

I have been experiencing repeated occurrences of "Card Err" messages. It usually starts with a "Cannot write to card" message. I've had the error occur against both slot 1 and slot 2.

The camera is configured to write RAW to slot 1 and Small Basic JPEG to slot 2.

The normal card configuration I use is a Class 10 SanDisk 32GB SDHC card in slot 1 and an Eye-Fi 8GB Pro X2 in slot 2.

However, I have tried the same model SanDisk card in both slots, I've tried various combinations of SanDisk 32GB Class 10 cards and SanDisk 8GB Class 6 cards, and I still get random failures.

Sometimes all I have to do is turn the camera off, remove and reinsert the card, and it works. Other times I have to also reformat the card. Simply turning the camera off, waiting, and turning it back on accomplishes nothing.

This just started this weekend -- the first time I've really put the camera through any workout. All occurred while the camera is mounted on a tripod using a SB-900 flash on the hot shoe. Except for "fixing" the card errors, the camera has remained on the entire time. I experienced about 10 to 12 failures (lost count) over a period of about 500 shots.

This problem is both annoying and unacceptable -- especially when I loose work!

Please tell me this is a known problem with a simple and fast fix!!

Anyone have any suggestions?