I am sorry I don't understand... unless you mean you have it installed on an USB memory stick, where you boot it from?

In that case it should be OK. I was wondering if you have a windows, and you are running linux on a virtual machine on top of the windows installation.

This does sound a bit strange; You are able to reach your N9 with flasher via USB port, so why does the booting N9 device not register on the USB bus when it should?

Can you check what "lsusb" command shows on the bus after you have the green text on the device?