Problem installing Virtualbox Guest addition on OMV 1.0

Today i did a fresh install (from iso) of OMV 1.0 on my system.

I've installed the extra's plugin and then installed virtual box.
Some of the virtual boxes i want to run need guest additions for passing trough usb devices.

So i tried to install the guest additions as described on the Virtuabox forum:

apt-get update
apt-get upgrade
apt-get install build-essential module-assistant
m-a prepare
mkdir -p /mnt/disk
mount -o loop /usr/share/virtualbox/VBoxGuestAdditions.iso /mnt/disk/
sh /mnt/disk/VBoxLinuxAdditions.run

The output is the following:

root@nas:/opt# sh /mnt/disk/VBoxLinuxAdditions.run
Verifying archive integrity... All good.
Uncompressing VirtualBox 4.3.16 Guest Additions for Linux............
VirtualBox Guest Additions installer
Copying additional installer modules ...
Installing additional modules ...
Removing existing VirtualBox non-DKMS kernel modules ...done.
Building the VirtualBox Guest Additions kernel modules
The headers for the current running kernel were not found. If the following
module compilation fails then this could be the reason.
Building the main Guest Additions module ...done.
Building the shared folder support module ...done.
Building the OpenGL support module ...done.
Doing non-kernel setup of the Guest Additions ...done.
Starting the VirtualBox Guest Additions ...fail!
(modprobe vboxguest failed)
Installing the Window System drivers
Could not find the X.Org or XFree86 Window System, skipping.
root@nas:/opt#

I can't seem to find what causes this....
Can somebody help me with this issue ?

Well i didn't even get to that part.

Just installing them om my OMV host device gives the error above.

Here some log files:

vboxadd-install.log
http://pastebin.com/dQe2BJLn

VBoxGuestAdditions.log

Starting the VirtualBox Guest Additions ...fail!
(modprobe vboxguest failed)
Starting VirtualBox Guest Addition service VirtualBox Additions module not loaded!

Ok so i think i am confused here.

Guest additions don't need to be installed on the HOST but inside the virtualmachiene ?

Any reason why an installation of a Ubuntu 10.04 LTS server edition virtualmachine on a Windows Host works perfeclty, and installing a the same using OMV as a host results in the lines "Guest additions not installed" in phpvirtualbox ?

I still have troubles getting it to work.

I copied the vdi disk image i've created on my mac to my OMV.
In OMV virtualbox (php) i create a new device with the VDi as source disk.
After booting into the system i installed the gues addtions inside the virtual machine, but still can get an internet connection to it.

On the phpvirtualbox screen it shows (Guest Network Adapter):

Ok, I resolved it.

The problem what that the eth0 interface whas not being detected insde the virtual box.
Together with the (Guest Network Adapters) message, i assumed it whas a problem with the Guest Addons.

After letting the VM redetect the ehternet interfaces, the problem is solved.

Sorry for the mixup!

I still seem to have some issues regarding the interfacing of the virtual box to the host.

I can't get the USB devices put trough to the guest.

Here is a screen shot the my phpvirtualmin usb tab:

if i do a lsusb command in my guest, the result is as following:

domoticz@domoticz:~$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
domoticz@domoticz:~$

Some webpages suggest is should add my user to the vboxusers group, but my guest system doesn't have that group.

domoticz@domoticz:~$ groups
domoticz adm cdrom sudo dip plugdev lpadmin sambashare
domoticz@domoticz:~$

Am I doing something wrong again or how should i fit this issue ?