USBPort causes Macbook's keyboard and mouse to not work on 2nd-stage setup

When I boot to the 2nd-stage setup using the latest master with vgal's USB patches applied, the mouse and keyboard aren't responding unless I replace the usbport.sys driver with the one provided by Windows XP. Then they respond as expected.

EDIT: Something changed since when I originally posted this ticket. Replacing the usbport.sys now has no effect.