What does this mean?

[jpff]

spamd[29973]: Attempt to free unreferenced scalar at 
/usr/lib/perl5/site_perl/5.6.1/Mail/SpamAssassin/Plugin/SPF.pm line 207, 
<GEN1460> line 48. 

Never seen it before and have been running SA3 for a while now.

==John ffitch