[Samba] rec_free_read bad magic

[Mark F]

I see this message repeating over and over in my logs.  What is the 
significance?

Nov  1 13:35:44 app1 nmbd[15488]:   tdb(/var/lib/samba/gencache.tdb): 
rec_free_read bad magic 0x42424242 at offset=460

Thanks,
-Mark