Are there any known problems with having file sharing/netbios enabled on Windows 2003 Server? The server wouldn't have any actual shares, just simply have it enabled. Would this be a problem on a public web server?
It is good practice to either disable or firewall a service that you are not using.
Bear in mind that on Window, the "Server" service is used for many things besides file sharing, and it is often desirable to leave it enabled. In this case, it should be firewalled so that the file sharing ports are not accessible from beyond the LAN.