I've also used Unibeast with 10.7.4 and BridgeHelper 4.0.1.
I have also tried different USB sticks to no avail.
Still getting: Waiting for root device.
I have tried -v, -x, GraphicsEnabler=No, PCIRootUID=1, PCIRootUID=0.
Any other way to try whilst avoiding USB? Perhaps copying Unibeast...