NetBIOS functionality enables client computers to register more than one NetBIOS name. If a NetBIOS name is unregistered by one system, and reregistered by another, Windows 2000 clients may not find the newly registered name.
When a Windows 2000 computer receives a negative session response from a 'server', it does not clear the NetBIOS over TCP/IP (NBT) name cache, causing an attempt to connect to the 'server' that originally had the name registered.
To workaround this issue, you can manually clear the cache by opening a CMD prompt and typing nbtstat -R.
If you are worried about forgetting, use Regedt32 to navigate to:
On the Edit menu, Add Value name TryAllNameServers, as a REG_DWORD data type, and set the data value to 1.