Hi Goswin,
My apologies, I sent my answer to you directly. Here it is again, but
this time with a propper list-reply:
Check that the bios and grub agree on the order of the drives. Try
running grub-install for the other drive or switch the mapping in
/boot/grub/device.map.
I forgot to mention in my first message that I have removed the second
drive in order to reduce to problem to the most simple setup. So right
now I have only 1 HDD as the primary master and 1 DVD player as the
secondary master.
Just to be sure I changed /boot/grub/device.map anyway [1], but it did
not help.
Thanks for the suggestion.
I get the feeling that the system somehow is not able to access or read
the MBR, but why that might be I am not sure. I thought of writing the
MBR anew, but this Live CD does not offer grub, nor grub-install. Do you
know if I can use a Knoppix 3.8.2 CD on an amd64 system without asking
for more trouble?