New NSM 3.1 install - issues

Hi,
I have just installed NSM 3.1 onto OES11SP1 servers, and am trying to get it to work.
I Have an NSM 3.1 server (Engine, Agent, Event), and a OES-FILE server (Home folders server, running Agent and Engine). All are authorised ok.
When I go to the Admin console, it says that there has been no heartbeat from the agent servers for more than 5 minutes, even though the time is 1 minute ago.

I don't know if this is the cause or a symptom, but I cann't get any events to show when I add/delete "test" users. Very frustrating.
I'm seeing many of these in the nsm server event log:
ES: Event message delivery failed with unknown status: 314.
and in the nsm server engine log:
01 2013-03-01 12:41:33 36000 3 8004 5221 7f1b08ef9700 WS: Error #314 reading Event Record Request from 172.16.0.36.

Any ideas? Or should I rip and replace?

Thanks.