[CentOS] Problems with kickstart installation into a Virtualbox

Hi listers
i tried to kickstart-install CentOS 6.0 64 in a Virtualbox (Virtualbox 
Version 4.12). I used a local CDROM with the net-install ISO on it to 
boot from. The ISO distribution file was provided on a server in the LAN 
as was the kickstart file.
When starting the installation i aded the following to the kernel line 
of the grub menu:
ks=http://install.mydomain.com/ks/centos.6.64.cfg

After i had corrected some errors in the kickstart file, the 
installation started as expected.
But it did not terminate as expected: after installing 198 of 671 
packages, the installation halted with an error (i.e. after installing 
the package libutempter).
In order to see what the problem was, i restarted from the CDROM in 
recovery mode, and after going into the half-way installed system, i saw 
in the anaconda log  that about three quarters of the post-installation 
scripts of the packages had returned a warning. The warning code was 
255. But the post-installation script of the package libutempter had 
returned an error with code 255, whereupon the installation  stopped.

I thought, OK, we will work around the libutempter package by selecting 
other program-groups in the kickstart-file. But i had no luck: the 
installation stopped then after the package  MAKEDEV.

Then i left off kickstart-installation and did a standard installation 
booting from the CDROM and getting the default packages from the server 
in the LAN. This worked fine.

-----

When it came to test the installed packages i was always lucky except 
with the package  fuse (fuse-2.8.3-1.el6.x86_64) which contains the 
binary /usr/bin/fusermount. This binary was installed without execute 
permission for everybody, so it could be invoked only by the userid root 
and members of the group fuse, which is not, what i had expected.

suomi