mounting WD external USB disk

[AN]

I'm trying to mount a WD "My Book" external usb hard drive, and am having 
a problem.

My system:
  uname -a
FreeBSD opteron.foo.bar 7.0-STABLE FreeBSD 7.0-STABLE #2: Wed Jun 11 
21:20:59 IDT 2008     root at opteron.foo.bar:/usr/obj/usr/src/sys/MYKERNEL 
i386

  camcontrol devlist
<PLEXTOR DVDR   PX-716A 1.08>      at scbus0 target 0 lun 0 (pass0,cd0)
<WD 5000AAC External 1.65>         at scbus4 target 0 lun 0 (da0,pass1)

Gnome 2.22.1

from /var/log/messages:

Jun 11 21:59:34 opteron kernel: umass0: <Western Digital My Book, class 
0/0, rev 2.00/1.65, addr 2> on uhub4
Jun 11 21:59:34 opteron root: Unknown USB device: vendor 0x1058 product 
0x1100 bus uhub4
Jun 11 21:59:34 opteron kernel: da0 at umass-sim0 bus 0 target 0 lun 0
Jun 11 21:59:34 opteron kernel: da0: <WD 5000AAC External 1.65> Fixed 
Direct Access SCSI-4 device
Jun 11 21:59:34 opteron kernel: da0: 40.000MB/s transfers
Jun 11 21:59:34 opteron kernel: da0: 476940MB (976773168 512 byte sectors: 
255H 63S/T 60801C)
Jun 11 21:59:34 opteron kernel: GEOM_LABEL: Label for provider da0s1 is 
msdosfs/My Book.
Jun 11 21:59:35 opteron kernel: pid 807 (hald), uid 560: exited on signal 
11
Jun 11 22:02:01 opteron kernel: GEOM_LABEL: Label msdosfs/My Book removed.

I tried a few different commands:

mount -t msdos /dev/da0 /mnt/
mount: Using "-t msdosfs", since "-t msdos" is deprecated.
mount_msdosfs: /dev/da0: : Invalid argument
[root at opteron ~]# mount_msdosfs /dev/da0 /mnt/
mount_msdosfs: /dev/da0: : Invalid argument
[root at opteron ~]# mount_msdosfs /dev/da0s1 /mnt/
mount_msdosfs: /dev/da0s1: Disk too big, try '-o large' mount option: 
Invalid argument
[root at opteron ~]# mount_msdosfs /dev/da0s1a /mnt/
mount_msdosfs: /dev/da0s1a: : No such file or directory
[root at opteron ~]# mount_msdosfs /dev/da0s1c /mnt/
mount_msdosfs: /dev/da0s1c: : No such file or directory
[root at opteron ~]# mount_msdosfs -o large /dev/da0s1c /mnt/
mount_msdosfs: /dev/da0s1c: : No such file or directory
[root at opteron ~]# mount_msdosfs -o large /dev/da0 /mnt/
mount_msdosfs: /dev/da0: : Invalid argument


Any help is appreciated, the exact command would be really helpful.

TIA