Mouse and Trackpad not working in FileVault 2 Login Screen

Neither my USB-mouse nor my Magic Trackpad are working in Login screen, when FileVault 2 is activated.

I set up File Vault 2 in Mac OS X Lion with Pre-Boot Authentication (PBA). In PBA-login my USB-keyboard is working, while using a wrong keyboard layout. I can neither use my magic touchpad nor an USB-mouse in PBA. Thus I can't change the keyboard layout located in the upper right corner. I tried unplugging all USB-devices except keyboard and mouse. Nothing seems to help and the mouse cursor isn't moving.

How can I get magic trackpad or USB-mouse to work in PBA login screen or manually set the used keyboard layout in PBA?

After talking an hour to Apple Support today there is still no solution in sight.