The Event Log on your domain controller contains:
Event Type: Error Event Source: NETLOGON Event Category: None Event ID: 5719 Date: 9/28/2001 Time: 4:12:55 PM User: N/A Computer: Server Description: No Windows NT or Windows 2000 Domain Controller is available for domain <domain name>. The following error occurred: There are currently no logon servers available to service the logon request. Data: 0000: c000005eYou may have run out of buffer space in the NetBT datagram buffer.
The default size of the NetBT datagram buffer is 128KB. Use tip 1243 to set the MaxDgramBuffering value name to a data value of 0x4000.
Restart the Netlogon service or restart your domain controller.