Bukkit

What steps will reproduce the problem?
1. Grant a group a permission
2. Negate it in a specific world
3. Test to see if a player in that group has that permission in that world (they do)

What is the expected output? What do you see instead?
World-specific perms should override global perms, so the player should not have a permission when they are in a world that negates it.

What version of the product are you using?
1.4

Do you have an error log of what happened?
No errors.

Please provide any additional information below.
Note that if a world negates a perm for a lower rank, but the player has a higher rank that explicitly grants it, it should stay granted (this is assuming higher ranks inherit from lower ones). Essentially, world-specific perms should be prepended to the global group that they modify, not appended like they are now.