I am using the RX320 application for remotely controlling the reciver, using remserial for the serial-over-ip.
I found that I received an error ("failed to clear RTS line") every time I attempted to connect to the reciever. I went into ORX320.CC and removed the serial error section beginning with "if (ioctl(_fd, TIOCMBIC, &modemlines))" and recompiled. Voila! It worked. I have been using the software for a couple days without issue.
I have yet to do research to determine if that error is required, but given that the RX320 reciever does not require the RTS or CTS lines on the serial port, I don't see yet a good reason to keep it in.
Just something to consider - I've got mine working.