Wsus no longer synchronising

My server has stopped updating the wsus catalogs.

The unhelpful error i am getting is as follows:


TypeInitializationException: The type initializer for 'Microsoft.UpdateServices.ServerSyncWebServices.ServerSync.ServerSyncProxy' threw an exception. ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send.
at Microsoft.UpdateServices.Internal.ClassFactory.CreateInstance(Type type, Object[] args)
   at Microsoft.UpdateServices.ServerSync.ServerSyncLib.GetWebServiceProxyInternal(UpdateServerConfiguration serverConfig, WebServiceCommunicationHelper webServiceHelper, Boolean useCompressionProxy)
   at Microsoft.UpdateServices.ServerSync.ServerSyncLib.GetWebServiceCompressionProxy(UpdateServerConfiguration serverConfig, WebServiceCommunicationHelper webServiceHelper)
   at Microsoft.UpdateServices.ServerSync.CatalogSyncAgentCore.RetrieveSubscriptionData()
   at Microsoft.UpdateServices.ServerSync.CatalogSyncAgentCore.ExecuteSyncProtocol(Boolean allowRedirect)


I really dont want to have to uninstall the whole thing.

Any ideas?

thanks