Networking OS X with a Windows server..?

I'm running version 10.3.9 -- i'm trying to connect to a computer running Windows Server 2003 R2 (service pack 1). I can see the other computers on the network, including the server.. but when i try to connect, i get a message saying "The alias "BIGBIRD" could not be opened because the original item could not be found." where "bigbird" is the name of the server.. at other times (when putting in a correct user/password for a dif user, i've gotten a msg saying that the user/password is wrong).. can anyone help me here?