MAC Address connecting to Port 1

Hi Folks,

Quick n00b question for you all. I recently purchased a D-Link DGL4300 
Router with NAT and SPI Firewall built in for my home network. I've 
disabled wireless access at the moment as im not currently using it and 
have configured the MAC filter  to only allow connections from the 2 
PC's i have on my LAN - the router is connected to my cable modem. All 
is working fine but when i check the logs i get this message regularly, 
about twice a day.

Wed Jul 13 08:20:05 2005 Access denied to system with MAC address ********** on port 1 



The MAC address is not always the same. so it seems something is trying to 
connect on port 1. now I've done a google and found that port 1 belongs to TCP 
Multiplexer and the following definition:




  A TCP client connects to a foreign host on TCP port 1.  It sends the
  service name followed by a carriage-return line-feed <CRLF>.  The
  service name is never case sensitive.  The server replies with a
  single character indicating positive ("+") or negative ("-")
  acknowledgment, immediately followed by an optional message of
  explanation, terminated with a <CRLF>.  If the reply was positive,"
  the selected protocol begins; otherwise the connection is closed.



Just wondering what could be trying to connect to port 1? If it's something 
legitimate or not?

Any help would be much appreciated.

Regards,

fac51