Make sure that Samba is actually running on your system. If you type "ps |grep smbd" at the command prompt, you should get something like:

root /opt/sbin/smbd -D

If not, you don't have samba running.

Dhival,
You might benefit from setting up swat to administer your samba configuration. It should have been installed with samba2.

You might want to try searching for it. Anyway, setup is at http://www.pogoplugged.com/forum/thread/15812/Optware-problems-on-Pogoplug-Pro/ .

Ok Andreas, you need to sign up to the yahoo groups forum like you did for pogoplugged.com at http://tech.groups.yahoo.com/group/nslu2-general/ and become a member to be able to download files. You will be welcomed there with open arms. You do know NSLU2 has a big European membership? There are various European sites and they want to add membership such as http://www.nslu2-info.de/ (they wanted a mention according to the website and are looking for English speaking moderators). If I got the wrong language, I apologize. NSLU2 is a truly world wide organization since it's membership (the guys that write the code) span multiple continents.

Hello Andreas,
I always assumed most Europeans are multi-lingual (my Father could speak 5). Where is the link to your config file? Anyway, for a Mac, make sure passwords are encrypted. Also, on the plug, check your permissions, owners, and groups to the share. So on the directory you are sharing, do "ls -la" and see if it and everything under it has read write permissions, and it's ownership and group are set to whichever user id is logging in. As a test, Log in as that user id with ssh to the plug and make sure you can create, edit, and delete files in that share. A while back, I used Seonbae's setup and it worked but permissions had to be fixed on my share with chmod, chown, and chgrp to match the correct user id.

You'd actually want to use /tmp/.cemnt/mnt_sdb1 as that is the path since it is the mount point. /tmp/.cemnt/sdb1 is the device entry.

Thanks for the help WarheadsSE! /opt/etc/samba/smbpasswd is the password file for Samba, like /etc/passwd is for the system (well, one of them). The smbpasswd command is in /opt/bin. It does indeed seem that Andreas did not place /opt/bin or /opt/sbin in the profile or download the profile from nslu2-linux.org.
WarheadsSE and I are just users and volunteers here, we do not work for CloudEngines. We actually have real jobs probably not related to plugs.
Make sure that when you do the command "smbpasswd -a username" that the username has been set up for the system. That is, the username that you choose must exist in /etc/passwd and /opt/etc/samba/smbpasswd so typing the commands "more /etc/passwd" and "more /opt/etc/samba/smbpasswd", both should show an entry for the same username that you chose. Once you have have successfully created your smbpasswd, you can try connecting to the share. On the Mac, it will try to log in with the Mac username. This might not work if it is different from the one you used on the plug. You would need to click on the "connect as" button and replace the username shown along with your samba password. If you get that far and it still does not work, you need to show us a copy of your share setting like you did for the general settings.