Bukkit

What is the expected output? What do you see instead?  Feel free to attach a screenshot or any error logs.
     Expected: Players don´t get money and xp for killing mobs in the restricted Area.
     Instead: Players still get money and xp for killing mobs in the restricted Area.

How can you reproduce the issue?  Please be as descriptive as possible, including any commands or in-game actions.
     1. Set-up MobArena
     2. Set-up restricted Area about the MobArena
     3. join MobArena
     4. kill mobs
     5. get money and xp

What version of Jobs plugin are you using?  Do not enter "latest" or anything similar.
     2.11.3

What version of Bukkit are you using (/version)?  Do not enter "latest" or anything similar.
     1.6.4.R2.0

RestrictedAreas.yml:
http://pastebin.com/iQSPrWRn

Okay restricted areas do work!

But if you set up y-value like 67 and try to kill mobs on y-value 67 its not working.

So you have to put the y-value at least one level beneath the level you are killing the mobs.

It's possible there is an off-by-one error in there if anybody wants to look at it.