Multiple FTP Login’s from my own IP?

I watch my system.log and console constantly and have noticed that every day on both my servers I get multiple FTP LOGIN REFUSED: getpwnam returned null coming from my own IP address. There are about 3 attempts per second but I cannot figure out whats causing this. It's happening on both my servers. One is a MacPro running 10.4.8 Server Universal the other on a G4 running Server 10.4.7. Anyone have any ideas?