Well, it seem's nobody could answer my questions...

For those wondering the same thing, I answered to my own questions. I cut the end of the wires included with the Ipac UIO and used a molex connector instead. You have to connect only the Up, Down, Left and Right pins If you keep connected with a USB cable. So power and ground wires are useless in this case.
I have to say that it's night and day in Hyperspin and emulators. No more weird reactions and much more easyer to configure!