From: otp_src_R11B-1/lib/kernel/src/inet_res.erl Look at the call to inet:stop_timer/1: gethostbyaddr(IP,Timeout) -> Timer = inet:start_timer(Timeout), Res = gethostbyaddr_tm(IP,Timer), inet:stop_timer(Timeout), Res. I guess the argument 'Timeout' should be 'Timer' instead !? --Tobbe