It shows up as COM port 1.
I do see a com port 1, but when i scan using the gps scanning app on the street deck cd it scans com1 (which is the only com port on the system) and it says there is no receiver present... the app works because i tested it with my bluetooth gps receiver, i still think its the drivers i just need conformation on the correct driver for that receiver..
I had a similar problem, I had a COM1 but even SD said there was no device found and wouldn't work.
I set the GPS device in SD to Disabled to have a play with the sat nav wihtout GPS and it magically worked.
Try re-installng the GPS drivers.