samba - Jan 2003 - nbtstat -A 192.168.0.1 returns "host not found"

Greetings,

I am running samba 2.2.5 win RedHat 8.0 Linux machine

Windows 2000 machine has fixed IP 192.168.0.40
Windows XP machine  has fixed IP 192.168.0.30
Linux machine has fixed IP 192.168.0.1 on eth0 (local network NIC) and
dynamic IP on eth1 (NIC connected to ADSL modem).

I can ping 192.168.0.1 ( linux machine) from all machines
I can ping 192.168.0.40 ( windows 2000 machine) from all machines
I can ping 192.168.0.30 ( windows XP machine) from all machines

I can mount windows 2000 shared folders with command bellow
mount -t smbfs -o username=administrador,password=123 //winbox/pub
/mnt/win2k

but what I want to do is to access files that I have in the linux
machine from windows.
I'd do that using "net use K: \\linuxbox\first" but it doesn't
work
command nbtstat -A 192.168.0.1 returns host not found but ping winbox
pings 192.168.0.1 ok
the command nbtstat -A 192.168.0.30 returns the shared resources on the
Win XP machine ok and viceversa
bellow it is my smb.conf. I've made it as simple as possible

;*******************section global*****************
[global]
	interfaces = 192.168.0.1/24
	workgroup = RIVENDEL
	server string = Teste Samba Server
	netbios name = Linuxbox
	security = share
	netbios aliases = elrond
	wins support = yes

;*******************section firstshare*****************
[first]
    comment = Our first samba share
    path = /samtest
    writeable = yes
    guest ok = yes


smbclient -L linuxbox returns the output bellow

added interface ip=192.168.0.1 bcast=192.168.0.255 nmask=255.255.255.0
Got a positive name query response from 127.0.0.1 ( 192.168.0.1 )

Domain=[RIVENDEL] OS=[Unix] Server=[Samba 2.2.5]

	Sharename      Type      Comment
	---------      ----      -------
	first          Disk      Our first samba share
	IPC$           IPC       IPC Service (Teste Samba Server)
	ADMIN$         Disk      IPC Service (Teste Samba Server)

	Server               Comment
	---------            -------
	ELROND               Teste Samba Server
	LINUXBOX             Teste Samba Server

	Workgroup            Master
	---------            -------
	RIVENDEL             LINUXBOX


Please help

R /
/ M