I formatted my Tomtom Go 920 internal memory by accident. When I have the tomtom connected to my Mac it shows two removal drives for my tomtom. One drive is 200mb and the other is 3.9GB. When I hook it up to my Pc the Tomtom only shows the 200MB drive.. I tried formatting on the PC and 200mb is all that is seen when you format it. What is going on? I would like to format it on the PC so I can reinstall my backup. I reinstall the backup on my mac the tomtom does not work and locks up.