Put the card in the Zumo. Plug the Zumo into the usb port on the PC. The PC should now see two more drives, one of which will be the SD card. Copy the MP3s across whichever way you like, and Robert is your mother's brother..................
It makes a big difference to the initial map drawing speed if you group your music files into folders, each folder holding about 20 files. If you just drag them all over as individual files onto your SD card map re-draw time can be anything up to 4 minutes. Stick them in folders and it comes down to about 15 secs.
Waldin posted something about this in his sticky about Zumo knowledge
Put the card in the Zumo. Plug the Zumo into the usb port on the PC. The PC should now see two more drives, one of which will be the SD card. Copy the MP3s across whichever way you like, and Robert is your mother's brother..................
Soundtaxi is a bit of software that will do what you want. I know it costs, and there are probably free alternatives, but I can say that it definitely does what it says on the tin.