Where is your gps antenna???
Here's why i ask:
GPS antenna in magnetic (sticks to metal). By "rules" it's supposed to be on the front of the dash, right next to the windshield. Not a good spot looks-wise if u ask me. So on my first dnx i simply sticked it to the side of the unit itself. It's metal, antenna is magnetic, so it works. Haven't had any issues with navi, exect for maybe (if it has anything to do with it at all) voice telling u where to turn/giving directions was breaking up once in a while. I returned the unit cuz it had some sound issues (volume controls not responding, usb cord not reading usb...)
Now when i got my replacement 5120 i sticked antenna to car's metal piece below/in the back of dnx. It worked fine the first day, no problems. Then it started to not see the sattellite. Sometimes while it says "looking for a settelite" i can just enter the adress i need to go to and it finds it right away together with the sattellite and the route. Sometimes it does not. I'll try repositioning antenna to the unit itself over the weekend to try to fix navi but apparantly i need to look for another place to put it. Prefferably not on the front dash.