Hi

I finally managed to get my Antminer U3 working (I was trying to mine Scrypt based currency with it - silly me)
I got a Pi with Minera and my own USB cord.

I get >90% error rate and don't understand why. Is it from the power supply? From the USB cord? 

What can affect error/rejected rate?

http://i62.tinypic.com/1192i3c.png