PortServer II 16 , problem talking to a DB9 with Realport.

Hi, I have a device using (DB9 - using Tx, Rx, CTS, RTS and SG)that I try to comunicate through realport but run into problem. When I plug this device into one of the serial port on my computer, it works fine. I have tried different (dev=host, mout and rp) but no luck. please help. Thanks