Network Not Showing Computers

[Muhnamana]

Alright, 3 machines running, two using Ubuntu 11.10 and one on Mac OS X.

On the two Ubuntu machines, both have samba installed and configured on the same workgroup, "HOME".

On machine 1, I can see all networked machines. On machine 2, I can only see the Mac OS X machine. It doesn't show the other Ubuntu machine.

What am I missing on machine 2 to see all networked computers?

Any suggestions are welcome. I'm pretty much stumped.

Thanks!

[Muhnamana]

To follow up on some observations, if I go to Network and press Ctrl + L and type in the following:

smb://192.168.1.203, I can connect to machine 1.

But when clicking on the homes folder, it says unable to mount location.