Garbled pictures when importing from 16GB Sandisk Extreme CompactFlash to MacbookAir

I am trying to Import my pictures in RAW format from my SD Card loaded in my Nikon D800 into iPhoto in my Macbook Air. I have done this process many times before.

This time, however, the imported images are showing up as garbled. Sometimes, they are completely white and, at other times, only sections of the images can be seen on the imported file. I can see the images clearly on the my camera viewer.

I am in the middle of a long-ish vacation primary at sea and have already taken some 200 pictures.

Any suggestions on :

(a) what can I do to import the pictures without such corruption?

(b) how can I ensure I do not lose my existing pictures?

© can I continue to shoot?