well don't try that lads, my 320 is now disabled for use outside uk ,,,, I have just mailed garmin for advice Go on the gps4us website n click there live chat, n speak with them they should be able to get you out the shit mate
just come off there site mate , very helpful but needed the receiver sent back , but would unlock for free , even went as far as to tell me there is unlocking software out there if your lucky enough to find it ,