I am having the same problem. My Nuvi 500 still shows caches in it when turned on but the GPX file is empty when connected to the computer. I read somewhere that this could happen if you are using a Mac and delete the file, you need to empty trash before disconnecting. It is very possible that I did delete them from my Nuvi while attached to the Mac and not empty the trash. Now what? I have contacted Garmin and am waiting for a response.