I am using Ubuntu 13.04 64-BIT as my host operating system running Virtual Box 4.2.10. I get this message when I tell virtualbox to install guest additions(CTRL+D),mounting the volume in the guest OS and run the VBoxLinuxAdditions.run file using root by:

sudo ./VBoxLinuxAdditions.run

It starts and then comes to these error messages:

Verifying archive integrity... All good.
Uncompressing VirtualBox 4.2.10 Guest Additions for Linux..........
VirtualBox Guest Additions installer
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 ...fail!
    (Look at /var/log/vboxadd-install.log to find out what went wrong)
    Doing non-kernel setup of the Guest Additions ...done.
    Installing the Window System drivers
    Warning: unknown version of the X Window System installed.  Not installing
    X Window System drivers.
    Installing modules ...done.
    Installing graphics libraries and desktop services components ...done.
    allusers@allusers-VirtualBox:/media/allusers/VBOXADDITIONS_4.2.10_84104$ 

I followed everything from the official VirtualBox manual on installing guest additions for linux I used some other commands such as:

sudo apt-get install build-essential linux-headers-$(uname -r) dkms

and:

sudo apt-get install virtualbox-guest-x11

I rebooted after executing those command and it still wont work. It still says the kernel modules are missing and the window is not seamless. Any idea what could be the problem?