Fixed with upload of:

grml2hd (1.3.0) unstable; urgency=low

  * Adjust grub handling to support grub2. [Closes: 
issue750]                                                                                                                                            
  * Fix handling of custom bootoptions in bootloaders.
  * Support ext4 filesystem.

 -- Michael Prokop <mika@grml.org>  Wed, 28 Oct 2009 18:04:27 +0100

Bugreport by Maurice McCarthy on grml mailinglist:

I have a new amd64 from DNUK with Ubuntu Jaunty pre-installed so I've
been experimenting with grml64 "Hello-Wien". It installs to the second
hard drive no problem provided lilo is used as the boot-loader. I
installed lilo to the mbr.

When I ran grml2hd with grub2 as the boot-loader it seems that
grub-install never ran as when it came to reboot I was presented with
the lilo graphic and it had to freeze on the default choice. Running
grub-install /dev/sdb from a chroot fixed it but prior to this the
device.map file read

(hd0)   /dev/vda

and there were no .mod files in /boot/grub in /dev/sdb1