Thanks you for your bugreport.

grub-common currently has a bug in debian regarding the generation of grub.cfg
(see <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=558255>)
apt-listbugs only shows you the bugs of the debian package and warns you before
you try to install the package.

So this is not a bug in grml but a problem with a debian package. Marking it
therefore as wont-fix.

Btw. grml2hd is not supported and not suggested if you do not know debian unstable. 
If you want to have a debian system with grml packages use grml-debootstrap to
install a stable debian system and install afterwards the grml packages.

Using version 2009.10 "full" (with default sources.list) installed with
"grml2hd" to a usb-stick.
"apt-get upgrade" stopps with this error message:

critical bugs of grub-common (1.97+20091115-1 -> 1.97+20091125-1) <unfixed>
#558255 - grub-pc: wrong boot partition in menu
Merged with: 558042 558243
Summary:
grub-common(1 bug)

Are you sure to...? Y/n? no

E: Sub-process /usr/sbin/apt-listbugs apt || exit 10 returned an error code (10)
E: Failure running script /usr/sbin/apt-listbugs apt || exit 10