Potential D800 and D4 CF card Fix
+1 ... or the disk administration tools (control panel) or similar tools. If needed, I use the HP USB Disk Storage Format Tool.
The larger the capacity of CF cards, the more likely it is that they contain bad bits. Usually these are mapped before the cards are shipped, but not always. When you format a card in a camera, essentially you are only performing a "Quick Format" which does not map the bad bits into the allocation table.
To correct this, remove the card from the camera and put it in a card reader connected to a computer. In PCs, select the card in My Computer (now listed as a drive), right click, and perform a FULL FORMAT. This will remap the card. DO NOT do a Quick Format as this will not re-map the card. Then put it in your camera body and do a camera format.
I had a Transcend 32GB 400X card that constantly gave me errors and locked-up my D4 regardless of whether it was the primary or secondary storage. After doing the above, I have had no errors or lock-ups.
Give it a try.
Michael E. Clark