I think the corrupt card message is a known bug in Ayufan's 6.0 image, and does not affect the use of the operating system.
Edit: ah, it was the 7.0 image I was thinking of (see here), but I guess the same holds true for the 6.0 image.
Edit: ah, it was the 7.0 image I was thinking of (see here), but I guess the same holds true for the 6.0 image.