I'm getting this error when running VirtualBox's installation script:

$ sudo ~/Downloads/VirtualBox-4.1.14-77440-Linux_x86.run 
Verifying archive integrity... All good.
Uncompressing VirtualBox for Linux installation...........
VirtualBox Version 4.1.14 r77440 (2012-04-12T16:20:44Z) installer
Removing previous installation of VirtualBox 4.1.14 r77440 from /opt/VirtualBox
Installing VirtualBox to /opt/VirtualBox
tar: Record size = 8 blocks
Python found: python, installing bindings...
Building the VirtualBox kernel modules

Error! Bad return status for module build on kernel: 3.2.6 (i686)
Consult the make.log in the build directory
/var/lib/dkms/vboxhost/4.1.14/build/ for more information.
ERROR: binary package for vboxhost: 4.1.14 not found

Here's the log:

$ cat /var/lib/dkms/vboxhost/4.1.14/build/make.log 
DKMS make.log for vboxhost-4.1.14 for kernel 3.2.6 (i686)
Sun May 13 14:32:52 CEST 2012
make: Entering directory `/usr/src/linux-headers-3.2.6'
/usr/src/linux-headers-3.2.6/arch/x86/Makefile:39: /usr/src/linux-headers-3.2.6/arch/x86/Makefile_32.cpu: No such file or directory
make: *** No rule to make target `/usr/src/linux-headers-3.2.6/arch/x86/Makefile_32.cpu'.  Stop.
make: Leaving directory `/usr/src/linux-headers-3.2.6'

/usr/src/linux-headers-3.2.6/arch/x86/ directory:

$ ls /usr/src/linux-headers-3.2.6/arch/x86/               
Kconfig        Makefile  ia32    lguest    mm        pci       tools  video
Kconfig.cpu    boot      kernel  lib       net       platform  um     xen
Kconfig.debug  crypto    kvm     math-emu  oprofile  power     vdso

Makefile references on "cpu"

$ cat /usr/src/linux-headers-3.2.6/arch/x86/Makefile | grep cpu
        include $(srctree)/arch/x86/Makefile_32.cpu
        # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)

Before upgrading to 3.X I didn't have this problem, the script would install VB correctly. Any ideas on what might be causing this?

Thanks in advance!