Okay I've played with it some more, and I think I have it working properly.
I set my COM port to 9600bps, then Xport at 4800bps, then in Iguidance/Oncore bumped it back to 9600. It's functioned reliably for several hours today. The only issue I've had, is off a cold boot into windows, the mouse goes crazy unless I unplug the gps and then plug it back in. I know I just need to change a registry setting to disable the serial mouse. So I think it's all good. I'm still waiting on my new windows license, so i'm not going to bother editing the registry until I get that installed.