What sort of interface are you using to connect your PC to your Pro2? In particular, how is this interface powered? Many such interfaces are powered via one of the serial port's modem control signals (RTS or DTR); if your interface is powered in this way, then open Commander's Config window, select the Ports tab, and set the DTR or RTS panel to "always on".
You might also find the following helpful:
http://www.dxlabsuite.com/dxlabwiki/TranceiverControlIcom 73,
Dave, AA6YQ