OS Cartridge NIC agent "Could not acquire an Agent Lock"

We're attempting to set up Foglight 5.6.5 OS Cartridge 5.5.4 on a host but are getting the following.  This does ring a bell for anyone as to what it might be? 

2013-09-03 11:48:01.790 VERBOSE [IncomingMessage-12189] com.quest.glue.core.comms.handlers.AbstractAgentLockMessageHandler - Could not acquire an Agent Lock from NIC_on_hq2drupal1.sfprod.businesswire.com needed before we can process the com.quest.glue.messages.schema.v1_3.SetAgentState_v1_3 message [msgId: 7cbd11f3-b6a9-4dd6-9877-809b5774aae9]. Will re-attempt lock acquisition in 4,000ms.

We've tried deleting and recreating the agent.  We're also using Unix Host Agent(Infrastructure Cartridge) to monitor the host but have network metrics turned off so as not to have duplicate monitoring.  We've found that the NIC agent gives more network statistics than the networking metrics in the Unix Host Agent.  This setup works fine for us on other hosts.  We're baffled by what this message means.

Thanks.

Stephen