I tried to update my Garmin Nüvi 3590 today. When I connected the device to my computer, Fedora 18 immediately connected the device as a USB storage device. Although this is typically desired, my Windows VM was then unable to take the device and connect to it so that I could update the maps. Annoying. I tried a few things, and none of them worked, so I finally started VMWare as root, started a copy of my VM (so that I did not change the permissions on the VM). What do you know.... when the VM runs as root, it is able to disconnect the device and connect it to the VM.