Steps to reproduce the problem:
My computer has a Gigabyte_GA-890FXA-UD7_(rev. 2.1) mainboard with AMD 890FX +
SB850 chipset. I run grml96-full_2012.05.iso or grml96-full_2013.01-rc1.iso and
choose grml64 from the boot menu. I boot into the console and mount a partition
on a sata harddrive (mount /media/sda2). On the partition I create a image of
another partition with dd which is 8GB. When I call sha256sum on that 8GB file I
get a different checksum for each run (sha256sum -b ./large_8GB_image.img). This
also happens with sha1sum and md5sum. Thus generating the hashsum of the SSD
which is the source of the image gives the same checksum fpr every run
(sha256sum -b /dev/sde).

This only affects grml64. Choosing grml32 from the bootmenu instead will show
the expected behavior: sha256sum -b ./large_8GB_image.img gives the same hashsum
for every run and it is identically to the hashsum of the source drive.