Submitted by Zidkon on dev bukkit:

What steps will reproduce the problem?

1. Spawn 10 spiders or cavespiders
2. Kill them

What is the expected output? What do you see instead?
I didn't configurated Spiders or CaveSpiders to drop Spider Eye, they do drop it.
Same with Creepers when they explode.

What version of the product are you using?
Using dev build 46913

Do you have an error log of what happened?
No, it doesn't show any error at console.

Please provide any additional information below.
Override logic says that it will override default minecraft drops of the mobs, and when some server owners gets a edited custom drop plugin, is almost because they need special drops and delete default minecraft ones, maybe make some items from default drops harder to get, etc, but if Override logic doesn't work so is useless for this kind of things, better block all mobs drops no matter how they died unless a player kills it don't you think?

Added config option to override default drops even when there is no reward in release 0.9.