I have a similar problem with my IUSB and Gemini cable. The blue USB works fine with IUSB and Micro IDSD. I would contact Ifi and set up a ticket.
Tom
I have discover something about my problem which you also have, the problem why it could not detect after connecting to the Gemini cable is because of the USB voltage. For some reason some PC USB port like my PC only supply 4.96V and thus I can never get it to work (IUSB + Gemini + IDSD Micro). I tried hooking it to a powered USB hub and it measure 5.12V and well suddenly everything works. So I suggest if anyone want to hook up like my config and happens to not work like mine, try hooked it up to a powered USB 2 or 3 HUB. It does work on my 1.5 yrs laptop though without any problem.