anchor.diff:  		    %% because the ACK might have a To-tag. If this happens, we must use 2543 methods to find
   		    %% the transaction even though RFC3261 17.2.3 only says we should do this if the ACK
   		    %% received does NOT have the 3261 magic cookie in the branch parameter.
  -		    logger:log(debug, "Transaction state list: Found no match for ACK transaction using RFC3261 methods, " ++
  +		    %%
  +		    %% Bug in RFC3261, see http://bugs.sipit.net/sipwg/show_bug.cgi?id=755
  +		    %%
  +		    logger:log(debug, "Transaction state list: Found no matching server transaction for ACK using RFC3261 methods, " ++
   			       "trying RFC2543 too"),
   		    get_server_transaction_ack_2543(Request, TransactionList);	
   		T ->
  
positive.code:     Id = {Branch, Method},
      get_elem(client, Id, TStateList).
  
  get_list_using_pid(Pid, TStateList) when record(TStateList, transactionstatelist), pid(Pid) ->
      case get_using_pid2(Pid, TStateList#transactionstatelist.list, []) of
  	[] ->
  
negative.code: 	    get_server_transaction_using_stateless_response_branch2(Id, T)
      end.
  
  %% Function: get_elem/3
  %% Description: Find a single element from a transactionstatelist
  %%              which has a matching type and id.
  %% Returns: TransactionStateRecord |
  %%          none
  %%--------------------------------------------------------------------
  get_elem(Type, Id, TStateList) when record(TStateList, transactionstatelist) ->
      get_elem(Type, Id, TStateList#transactionstatelist.list);
  
  