Bind log

["David Priban" <david2@maincube.net>]

I'm not sure if this is security related but this line
shows up in my log file every so often:

Feb  6 09:43:01 prophit named[30447]: bad referral (NET !< APNIC.net)

The NET and domain name part is changing.
Can somebody tell me what does it mean?

Thanks everyone
David