NO 64bit option to create a new Virtualbox machine

[oxy]

hi,

i wanna install Win8 on Virtualbox inside my ubu 12.04 64bit.

Vbox gave me no option for win8 64bit (only 32bit available) when
creating a new machine. Thus i googled ...

On the page: https://www.virtualbox.org/manual/ch03.html

I found: Warning:

1) you should enable the I/O APIC
2) make sure that the VM uses the Intel networking device

In my Vbox settings it checked:

Vbox settings -> System -> Enable IO APIC (checked)

Vbox settings -> Network -> Advanced -> Adapter type -> Intel PRO/1000
MT Desktop

It seems that i satisfy both criteria. However when i try to create a
new virtual machine on Vbox i still have only 32bit options. No 64bit
system available! Any other idea?

Thx...

Vbox version: 4.3.16 r95972