Most likely the problem you are having is caused by the SMB protocol itself. Its a broadcast protocol that does self announcements. As mentioned previously it can take upwards of 15 minutes for one machine to register with another on the network. If I remember correctly its an announcement, verification request, confirmation kind of thing.
You should be able to do
start->run \\amiga_name\share from the pc and see files on your amiga.
Now I don't know about the various problems with ports, but if there was a problem and some point with nmbd than it could definitely be the root cause of the name not showing up.
The two parts of samba are smbd which handles the server message block protocol for the file and print sharing and nmbd which is the NETBIOS name server. Basically, nmdb handles name resolution and discovery ie. Network Neighborhood. You can still use Samba without nmbd running it just doesn't know how to discovery other machines via broadcast.
This is not a problem for modern windows boxes because they can all use ip addresses to conenct other machines. So one other thing you can try is \\amiga_ip\share and the same should work from the amiga.
Now the fact that the pc name works from the samba side would elad you to believe that nmbd is working but its possible its receiving find and not sending the udp packets correctly.
Using ip addresses is annoying so you can compensate by using the DNS name of the machine (but you probably aren't running DNS in house) or by editing the local windows hosts file to match your amigas ip and name. The hosts file can be located in c:\windows\system32\drivers\etc\hosts. Just add
. There is a sample in the file so, its pretty self explanatory. You must have a static ip for your amiga (no random dhcp address). for this to work. This way you can use \\amiga_name\share all the time. Also you can use map drive to make the connection occur all the time so you won't need to use netowrk neighboorhood or manually make the connection constantly.
So in summary you can try the following:
1) Wait over 15 minutes.
2) Upgrade your samba to the latest stable port (this should probably be step one 
3) Not use network neighborhood and just use the ip address or hard code the ip/name in your windows hosts file so you can use your amiga's name
Let me know if you have any other questions or any of the above doesn't make sense.
