Samba works only sometimes

[Markus Lutzer]

I use Ubuntu Edgy on two computers connected via Ethernet (cable -
switch - cable). I configured Samba on both machines to share files
without authentication. Most of the time I have trouble to access files
from the other computer.  Opening network servers in Nautilus does not
recognize the other computer. But sometimes it works. I have the problem
also if I use Windows on one of the machines. But sometimes it works and
I don't know why. While having the problem I tried two times to mount a
directory via mount by providing the specific IP address and directory.
This seems to work. Internet is working quite well thus the network
seems to be fine. It doesn't matter if I connect from computer A to B or
vice versa. Any ideas how to encircle the problem?