My MAC address has changed depending on the firmware I'm using. The firmware it came with looked like Mns's 0809 rom but programs error-ed a lot and maps wouldn't open. I filter MAC addresses on my routers so I had to record this. I then tried the 0809 rom from Wits. I had a different MAC address. After verifying that I had a GPS unit I flashed back to 0809 Mns rom and got a different MAC again. So far it's much more stable after I went with a fresh Mns rom install. Everything opens that should.A side note.When I started it up when I got it, it would show the 4 colored boxes on startup. After I flashed stock it showed the grass/water. After I flashed 0809 Mns again I still have the grass/water.