Many people say that it is necessary to install the program GPSFlex to make the TomTom work in the Omnia. This is sometimes true, depending on your Omnia´s ROM, but this program seems to drain off your batteries and to heat your device up. I made a quick test today and with mine, GPSFlex was not necessary at all.
My Omnia comes with the default Orange ROM. What you have to do is:
1.- Configure GPS as: “Other NMEA device”, speed: 4800, COM3. The GPS device should be detected almost immediately.
2.- It sometimes takes 2 or 3 minutes to get a valid GPS signal. If after several minutes it doesn't do it, try switching off your Omnia (with a long push in the power button). After reboot, it should get signal. Some people said that it helps to deactivate your phone before switching off, but this seems a bit weird to me. However, you can try…