I have encountered an interesting problem I have not seen here before. When I followed the instructions to unlock CityXplorer Sydney with Jetmouse KG and transferred the img and unl files to my SD card /Map folder it worked beautifully (showed up as Powered by Cityxplorer - was able to simulate a route etc.). I then proceeded to Melbourne, used the same procedure - Jetmouse with same ID (2354 for CN AusNZ 2012) and PID2 settings. After transferring it to my Nuvi (same directory SD/Map as Sydney) and powering it up, the message appeared 'cannot unlock maps' and Melbourne was not seen in the Map info screen as was Sydney. I then tried Brisbane and Adelaide following the same procedure with the same negative result. Has anyone come across this before. Can maps unlocked using Jetmouse with the same ID signature (although with different unl file names) not be used in the same GPS?