Eu acho que isso está apontando para o serviço 'master computer browser' no PDC emulado - possivelmente está parado, você provou que o netbios sobre o tcp está funcionando, então podemos descartar isso - não é configuração DNS ou sufixo de domínio sua interface, como 1) funciona com FQDN 2) não queremos usar o FQDN. Então, eu arriscaria que 'Computer Browser Server' é onde está o problema. É possivelmente parado como resultado de um processo eleitoral e agora está executando em diferentes 'mestres' uma máquina que pensa que é mestre e forças e eleição.
Browser Elections, Browser elections occur to select a new master browse server under the following circumstances: When a computer cannot locate a master browse server.
When a preferred master browse server comes online.
When a Windows-based domain controller starts.
When a back-up browse server cannot contact the master browse server to obtain updates to the browse list.
a solução de problemas por que o serviço do navegador foi interrompido é referenciada neste artigo kb de causas comuns link
qual é esse serviço?
Browser service or Computer Browser Service is a feature of Microsoft Windows to let users easily browse and locate shared resources in neighboring computers. This is done by aggregating the information in a single computer "Browse Master" (or "Master Browser").
Se você atualizou recentemente uma caixa do servidor Windows 2003, vale a pena citar: link
Computer Browser Service Windows Server 2008 sets the startup state of the Computer Browser service to disabled by default for a new installation of Windows Server and when upgrading an existing server to Windows Server 2008. The Computer Browser service helps maintain an updated list of domains, workgroups, and server computers on the network and supplies this list to client computers upon request. For detailed information about Computer Browser service operation, see Appendix C - Computer Browser Service. The default startup state of the Computer Browser service on computers running Windows Server 2008 can cause problems for a domain controller in the primary domain controller flexible single master operations (PDC FSMO) role. For computer browsing, a computer in the PDC FSMO role centrally collects and distributes information about domains, workgroups, and computers for multi-subnet networks. If the computer in the PDC FSMO role is not running the Computer Browser service, computer browse lists across the network will contain only domains, workgroups, and computers on the local subnet. To prevent this problem, configure the startup type for the Computer Browser service for Automatic on the computer in the PDC FSMO role and then start Computer Browser service. You can do this from the Services snap-in or at an elevated command prompt with the following commands: sc config browser start= auto sc start browser Because the Computer Browser service relies on file and printer sharing, you will also need to turn on File and Printer Sharing in the Network and Sharing Center. Alternatively, move the PDC FSMO role to another domain controller that has the Computer Browser service started and configured for automatic startup and File and Printer Sharing turned on in the Network and Sharing Center. Additionally, if the only server computer on a subnet is running Windows Server 2008, client computers will become the local browse server on the subnets. As client computers are started and are shut down, the role of the local browse server will pass from one client computer to another, possibly resulting in an inconsistent display of domains, workgroups, and computers. To prevent this problem, on the computer running Windows Server 2008, turn on file and printer sharing, configure the startup type for the Computer Browser service for Automatic, and then start the Computer Browser service.