I'm running Ubuntu 12.04 (desktop) and have virtualbox installed. I'm trying to install another Ubuntu in virtualbox using a memory stick and don't manage

Installed is:
wim@i3-2120:~$ dpkg --get-selections |grep virtualbox
virtualbox					install
virtualbox-dkms					install
virtualbox-guest-additions			install
virtualbox-guest-additions-iso			install
virtualbox-guest-dkms				install
virtualbox-guest-utils				install
virtualbox-guest-x11				install
virtualbox-ose-guest-utils			install
virtualbox-ose-guest-x11			install
virtualbox-qt					install
First of all I can't select USB2.0; it tells me that 'this requires the Oracle VM VirtualBox Extension Pack to be installed'; did I miss a package in Synaptic? Secondly, when pressing F12 for boot options, there is no option for the memory stick (related with first issue?). When I move the mouse over the USB icon, it sees the memory stick (possibly not immediately).

Any assistance is appreciated.