Thanks for the heads-up, I'll stick to the thread

By now I tried it on 4 different machines, two with native COM-ports and two with a USB-Dongle, all fail. Most of the time I get the "data fail", sometimes a "receive no data". Can anyone check their COM-port settings please?
Mine are "standard", i.e. 9600bps, 8 data bits, no parity, 1 stop bit and no flow control. FIFO-Buffer is enabled.
Edit: I just got word from RSOV, they told me that after connection the radio LCD is supposed to show "PC". That never happens in my case.