Access USB disk via LAN

[sness]

I have a USB disk (my book) connected to a laptop that should be available to Windows users. I have installed Samba, and can access the disk from other machines, but not the USB disk. The USB disk is shown in the network, but when I try to access the disk I get the message: The disk is not awailible.
I can’t change the permissions on the Disk in Nautilus.

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root@sn-laptop:/etc# fdisk -l

Disk /dev/sda: 20.0 GB, 20003880960 bytes
255 heads, 63 sectors/track, 2432 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xd890d890

Device Boot Start End Blocks Id System
/dev/sda1 * 1 1216 9767488+ 83 Linux
/dev/sda2 1217 1475 2080417+ 83 Linux
/dev/sda3 1476 2432 7687102+ 5 Extended
/dev/sda5 2312 2432 971901 82 Linux swap / Solaris
/dev/sda6 1476 2268 6369709+ 83 Linux
/dev/sda7 2269 2311 345366 82 Linux swap / Solaris

Partition table entries are not in disk order

Disk /dev/sdb: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x5c74ae42

Device Boot Start End Blocks Id System
/dev/sdb1 1 30401 244196001 c W95 FAT32 (LBA)

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root@sn-laptop:/media# ls -la
total 58
drwxr-xr-x 7 root root 4096 2009-06-15 10:26 .
drwxr-xr-x 21 root root 4096 2009-06-12 21:23 ..
lrwxrwxrwx 1 root root 6 2008-06-23 18:44 cdrom -> cdrom0
dr-xr-xr-x 10 root root 2048 2008-10-30 00:24 cdrom0
drwxr-xr-x 21 root root 4096 2007-10-19 08:02 disk
lrwxrwxrwx 1 root root 7 2008-06-23 18:44 floppy -> floppy0
drwxr-xr-x 2 root root 4096 2008-06-23 18:44 floppy0
-rw-r--r-- 1 root root 232 2009-06-15 10:26 .hal-mtab
-rw------- 1 root root 0 2009-06-13 22:18 .hal-mtab-lock
drwxr-xr-x 11 root root 4096 2008-06-23 18:40 -home
drwx------ 17 sn root 32768 1970-01-01 01:00 My Book
root@sn-laptop:/media#