anchor.diff:  %% Returns : ok
   %%--------------------------------------------------------------------
   parse_do_internal_error(Header, Socket, Status, Reason, ExtraHeaders) ->
  -    {_, Method} = sipheader:cseq(Header),
  -    case Method of
  -	"ACK" ->
  +    case sipheader:cseq(Header) of
  +	{unparseable, CSeqStr} ->
  +	    logger:log(error, "Sipserver: Malformed CSeq (~p) in response we were going to send, dropping response",
  +		       [CSeqStr]);
  +	{_Num, "ACK"} ->
   	    %% Empirical evidence says that it is a really bad idea to send responses to ACK
   	    %% (since the response may trigger yet another ACK). Although not very clearly,
   	    %% RFC3261 section 17 (Transactions) do say that responses to ACK is not permitted :
  
positive.code: 	    %%   retransmissions or disallowed responses (such as a response to ACK).'
  	    logger:log(normal, "Sipserver: Suppressing parsing error response ~p ~s because CSeq method is ACK",
  		       [Status, Reason]);
  	_ ->
  	    transportlayer:send_result(Header, Socket, <<>>, Status, Reason, ExtraHeaders)
      end,
      ok.
  
negative.code: 		    throw({sipparseerror, request, Header, 400, "CSeq Method " ++ CSeqMethod ++
  			   " does not match request Method " ++ Method});
  		true -> true
  	    end
      end,
      case yxa_config:get_env(detect_loops) of
  	{ok, true} ->
  