Fixed with:

commit f6065cb30e016a76a450ce8aefa91722624b0770
Author: Michael Prokop <mika@grml.org>
Date:   Sat Sep 4 12:27:21 2010 +0200

    Update isolinux.bin and vesamenu.c32 to 4.02 debian-20100803.
    
    Taken from syslinux-common 2:4.02+dfsg-3.

We decided to continue using the files shipped by grml-live and grml2usb uses 
the isolinux files from the syslinux package of the host (if present).

regards,
-mika-

On Thursday 12 August 2010 14:42:06 Ulrich Dangel wrote:

> grml-live should contain the newest isolinux files in the template
> directory as the new syslinux (4.0) contains different modules.
> Problem is that debian stable still has 3.x, so we would need to adjust
> grml2usb to work with different version (replace the files on the disk
> with the ones from the distribution for example)

Btw. what is the reason that grml-live contains all the files in the template 
directory? Can't we copy it from syslinux-common?

regards,
Ulrich

Hi,
grml-live should contain the newest isolinux files in the template directory as the new syslinux (4.0) contains different 
modules.
Problem is that debian stable still has 3.x, so we would need to adjust grml2usb to work with different version (replace the 
files on the disk with the ones from the distribution for example)

For some details see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=591635

Marking it as release stopper as the issue should be resolved before releasing a new version.

regards,
Ulrich