uploading sketch to Arduino ethernet with Arduino mini USB does not work.

I cannot upload a sketch to Arduino ethernet with Arduino mini USB, I am getting the "Avrdude" error
message. I connected the mini USB board to the Arduino ethernet as in the example shown. Weird is that the L9 Led is constantly on. Is that correct ? If I press reset it goes off and comes on again. Loopback test, connecting Tx to Rx on the mini USB works fine. However, measuring with oscilloscope, when I connect
mini usB Tx to Arduino Rx the signal on that connection goes to +5 and stays there. No change in the signal when I send something with the serial monitor. I don't understand what is going on.