USB hub loses the connection to the laptop again

I bought the machine because I have not enough USB ports on the laptop. Unfortunately, I had zuemlich quickly following problem:

The cordless mouse was repeatedly disconnected from the system (No signal, even though the mouse facilitated tete). After I turn the stroke and had been cooked up again, we went back some time. He has my external hard drive not at all recognized (Intenso 500GB and 1TB Medion). Therefore, no good evaluation and return. Too bad, looked very chic.