Have you restarted the BES more than twice so far? If so the service may have been disconnected at RIM. This is a security precaution in the event someone impersonates your BES. The RIM network will not allow two instances of the service to run. You can check the notes log or view the domino console for any errors related to failed connection to SRP host. However that would not prevent you from connecting thru the BM.
Go to your admin wrkstn and from a cmd prompt at the "Notes" dir where the executables are located....run the following test "NDCTEST". This will determine if the "client" wrkstn can connect via NRPC. Just follow the prompts. You'll be asked for the sever name....use the full heirarchical name and you'll be prompted for a password...use you notes password. If that fails you have an issue within your DNN.