[Samba] Remote connection to Samba service doesn't work

[Mateusz Szymaniec]

Hi.
I've got a nasty problem with Samba. Basically, I can't connect to my
Samba service from a home laptop (running Windows 7). I guess that on
this side everything is fine, I'm using my corporate Samba shares via
VPN, I've been using Samba on my previous server and it was running
OK. I've asked my buddy living nearby to connect and it didn't work
for him, as well as for 15 other people across living my country. The
weirdest thing is, that there are actually people that are able to
connect. They were using both Windows XP and 7 and I can't really tell
why. I see their connections in logs, but I can't really tell a
difference between my and theirs setup.
I've tried to use default Debian Etch 2.x Samba, 3.x backports
version, compiled 3.x from sources, even reinstalled operating system
on the server. I've used default config, copied one from my previous
server, wrote it from stretch server times. Every single time it was
possible to connect locally (smbclient -L localhost). On the client
side, I've tried using default Windows 7 (and XP) smb/cifs
implementation and cygwin's smbclient.
My server ISP tells that they don't block anything and it's the first
time someone has reported problem like this. My iptables are clean at
the moment.
Currently I'm using v. 3.2.5 with default config with one share and
added user by smbpasswd.

revik:~# smbclient \\\\localhost\\test
Enter root's password:
Domain=[REVIK] OS=[Unix] Server=[Samba 3.2.5]
smb: \> ls
 .                                   D        0  Fri Dec 31 13:57:25 2010
 ..                                  D        0  Fri Dec 31 13:57:16 2010
 testfile                                     0  Fri Dec 31 13:57:25 2010

               35201 blocks of size 8388608. 33290 blocks available
I don't really can think of any single idea how to make it work or
where the problem actually lies.
I'd appreciate any help, thanks.