I'm trying to install Ubuntu (64 bit) as a guest operating system in VirtualBox. My setup is an Intel i3 machine with Windows 7 (64 bit) and VirtualBox 4.3.4r91027 (latest version). I went through the setup wizard to create a new virtual machine, but when I try to boot Ubuntu it complains that it doesn't have an x64 CPU.
Per results of a Google search, I checked settings for VT-x/AMD-V (already enabled) and I/O APIC (enabled it but same result).
What am I missing?