Hi Mark, Can you try compiling a kernel with the patch from this email: http://marc.info/?l=linux-usb&m=133301247601831&w=2 I think it might fix your issue with the Set Address command failing. Can you enumerate other USB 2.0 devices on the USB 3.0 port after you plug in your Prolific mass storage device? I suspect you won't be able to. Do other devices get enumerated when they're plugged into the USB 3.0 port? Sarah Sharp -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html