Connecting a Samsung Galaxy S3 in Ubuntu 13.04

Solution 1:

I had problems mounting Android devices by myself. Maybe you forgot to unlock your android device. As long the security log is activated (pattern or number) the fuse-MTP module will not be able to mount the device, which is quite sensible from a security view.

Solution 2:

I dont know if this will help, but mine does that "unable to mount" repeater to, but that is because it is recognized as a device, but then 10 seconds later it disappears and reappears as a usb media device, then it mounts.