I was looking at the log files and discovered that pidentd was throwing error messages about netlink_lookup: write failed: Connection refused
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=305926
Seems to suggest that adding the module should make it shut up.
So I added the following to /etc/modules # tcp_diag may shut pidentd up about netlink_lookup: write failed tcp_diag