it's not a bug, ist's a feature :-)
Just click the little "ghost" icon in the in the material- or atmosphere browser and you'll never see the cornucopia content again.
easy enough :-)

Quote -
But the best thing was when i opened up the new materials and thought like "Ah, paint - cool that they added this" and you select the material and it asks you to buy the materials from cornucopia now. THATS REALLY NASTY! Eon you mean old men, if you dont wanna include a material, then leave it out. I dont pay over 200 bucks for a software that always tells me like "Buy this now, buy that then". This is how these ringtone companies rip off teenagers, but no professional business behaviour. AT LEAST ONE DAMN MATERIAL SHOULD HAVE BEEN INCLUDED IN THAT CATEGORY. Then i could maybe have forgiven eon.