anchor.diff:  %% REGISTER request had no contact header
   process_updates(_LogTag, _Header, SipUser, []) ->
       %% RFC 3261 chapter 10.3 - Processing REGISTER Request - step 8
  -    {ok, {200, "OK", [{"Contact", fetch_contacts(SipUser)}]}};
  +    {ok, create_process_updates_response(SipUser)};
   
   process_updates(LogTag, Header, SipUser, Contacts) ->
       %% Processing REGISTER Request - step 6
  
positive.code: 
  %% return = ok       | wildcard processed
  %%          SipError   db error
  %% unregister all SipUser entries
  unregister(LogTag, Header, _SipUser, Locations) ->
      %% unregister all Locations entries
      F = fun() ->
  		unregister_contacts(LogTag, Header, Locations)
  
negative.code: 		end,
  	    case mnesia:transaction(F) of
  		{aborted, Reason} ->
  		    logger:log(error, "Location database: REGISTER request failed to add/update/remove one ",
  			       "or more contacts for user ~p, failed due to: ~n~p", [SipUser, Reason]),
  		    %% Check if it was a siperror, otherwise return '500 Server Internal Error'
  		    case Reason of
  			{throw, {siperror, Status, Reason2}} ->
  