Spider eye doesn't drop after world copy

Hello. I'm playing single player survial mode and there is no spider eye in drop from spiders (killed by hand or sword). I try to create new world and i get a spider eye from spider. Then i make a copy of new world and killed about 10-15 spiders and there is no spider eyes in drop. Is that a bug?

 

Add: It seems for me that in current beta 1.7.0.5 there is no bug. Spider eyes drop fine.

 

Device nokia 6.1