Can not see network computers

[Pedro Santos]

When I try to access to network servers, with Ubuntu 5.10, always
receive a request to enter my username, password and domain for
authentication.
I can not see my network computers, only appears the "Windows Network"
icon. The only way to access a network computer is to enter his path.
With Ubuntu 5.04 this does not happens. Can anyone help me to solve
this?

Thanks
Pedro Santos