HP ProBook 4730s - enabling vt-x

I'm working on a new DevOps system that relies upon Chef, Vagrant and VirtualBox.  To duplicate the system I needed to run Ubuntu Trusty 64 bit edition in the virtual box.  Vagrant setup failed with timeouts.  When I ran the 64 bit VM Vagrant made through the VirtualBox client it said I did not have VT-x visualization on my machine.

I have a HP ProBook 4730s.

As you can see it uses i5-2430M CPUs.  Checking at http://ark.intel.com/products/53450/Intel-Core-i5-2430M-Processor-3M-Cache-up-to-3_00-GHz , shows that :

So, why won't VirtualBox work?  The answer lays in the HP bios.  To enable:

Restart notebook.
Press F10
Choose system features
Device features
Virtualisation
check.
Save
Reboot.

VirtualBox still refuses to run ubuntu 64.  Some googling reveals you have to enable the bios to change the setting, rather than just view.  WTF?

Restart notebook
Press F10
Choose security
Some stupid setting
save
reboot

Now it works.