My guess is that there is something wrong with the driver-installation (or something else in your Ubuntu installation). You should see the driver loaded even when no devices are attached (like this):

$ lsmod | grep vhci
usb_vhci_iocifc        36864  4
usb_vhci_hcd           40960  2 usb_vhci_iocifc

I'm no kernel-driver expert but you could start by checking that the driverfiles are installed in

/usr/lib/modules/`uname -r`/

I think the mounting will start working once you figure out why the driver isn't loading...