Confirming delta import from connector throws exception

When attempting a confirming delta import delta sync after a successful export, the following exception is thrown in the new Aurion demo environment (FIM, using Windows 2k8). This is thrown as a stopped-extension-dll-exception in FIM. According to Patrick, this error has not been seen before in other environments. It has been remedied by performing a confirming full import full sync instead.

The extensible extension returned an unsupported error.
The stack trace is:

"System.ServiceModel.CommunicationException: An error occurred while receiving the HTTP response to http://localhost:59990/IdentityBroker/RemoteXmlAdapter.svc. This could be due to the service endpoint binding not using the HTTP protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the service shutting down). See server logs for more details. ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a receive. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
— End of inner exception stack trace —
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.PooledStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.Connection.SyncRead(HttpWebRequest request, Boolean userRetrievedStream, Boolean probeRead)
— End of inner exception stack trace —
at System.Net.HttpWebRequest.GetResponse()
at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
— End of inner exception stack trace —

Server stack trace:
at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason)
at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at 0:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at Unify.Framework.ILDIFAdapter.ImportChanges(Guid adapterId)
at Unify.Framework.IdentityBrokerManagementAgentProxy.GenerateImportFile(String fileName, String connectTo, String user, String password, ConfigParameterCollection configParameters, Boolean fFullImport, TypeDescriptionCollection types, String& customData)
at Unify.Framework.IdentityBrokerManagementAgent.GenerateImportFile(String fileName, String connectTo, String user, String password, ConfigParameterCollection configParameters, Boolean fFullImport, TypeDescriptionCollection types, String& customData)
Forefront Identity Manager 4.0.3531.2"

WCF logging should be enabled to diagnose the true error.