With MuVo 128 one can use linux programs from
dosfstools debian package.
There is one subtility - I have had to specify FAT 12 to mkfs.vfat
to get normal transfer speed on MuVo. With FAT 16 it takes much
more time.
mkfs.vfat -F 12 /dev/sda1
If there is a problem with available space one can use
fsck.vfat -a /dev/sda1 to repair all lost clusters.