Lexar JumpDrive mount problem

I'm having problems with a Lexar JumpDrive. When I plug it in, it creates an entry is fstab like this:
/dev/sda /mnt/diskonkey auto noauto,owner,kudzu 0 0

When I try and mount it using the Disks menu from the Gnome desktop, I get:

Nautilus was unable to mount the selected volume.
and
mount: I could not determine the filesystem type, and none was specified

If I mount it manually using :
mount -t vfat /dev/sda1 /mnt/diskonkey
it works fine

If it makes any difference, the command:
usbmodules --device /proc/bus/usb/001/008
gives me:
usb-storage

How can I change the device and mountpoint that it defaults to?

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Ryan