ntpd "Invalid argument" messages in log

I noticed that ntpd was generating a bunch of these messages in my logs.

Jan 14 06:05:14 starbug ntpd[5574]: sendto(xxx.xxx.xxx.xxx) (fd=22): Invalid argument
Jan 14 06:05:36 starbug ntpd[5574]: sendto(yyy.yyy.yyy.yyy) (fd=22): Invalid argument
Jan 14 06:05:40 starbug ntpd[5574]: sendto(zzz.zzz.zzz.zzz) (fd=22): Invalid argument

A quick Google search will tell you that this happens when your interface changes. In my case, my dynamic IP address from my ISP had changed. Restarting the ntpd service will correct the problem.