The culprit is toram. This command line:

linux (loop)/boot/grmlmedsid/linux26 quiet lang=de boot=live noeject noprompt
keyboard=de isofrom=/dev/cciss/c0d0p1/boot/grml/grml.iso serial
console=ttyS0,115200n8 ssh=1234 ignore_bootid                            

works fine with today's image.