Make sure the devices are paired aswell and the N900 has your other device set to a trusted device so it can automatically accept incoming connections from it, failing that. I've only tried it with my laptop and N810, I would if Columbus is saying it's using channel 2, then I guess setting COM port to 2 should do the trick. Other than that, find out from the other software distributor what you should do to get it to connected to a Bluetooth serial port that is using channel 2 and streaming NMEA data.