Problem/Bug Items changing by left click!!

Hi there guys, i'd be really glad if anyone could help me...
Well, i'm running a Minecraft Bukkit Server 1.7.2 (it's been a while since I started it... more than a year, I think)
This problem/bug kinda of always been there, but only now, I decided to create an account and do something about it.
So... Let me explain:
FOR INSTANCE: If i'm holding like... hm... a potion of speed (not necessarily a potion) and whenever I break something holding it, the potion will change to a water bottle (which is the raw id of that item)
So basically... destroying a block (or whatever) will turn the thing in my hand to it's brute id, regardless of it's modifications (like, Chiseled Stone Bricks --> Stone Bricks ; Spruce Wood Planks --> Oak Wood Planks)

Is it a common bug?? Does anyone know how to solve it?? Please I need help to move on in the server's progress... Thank you so much already

My plugin list:
-AttributesAPI
-Citizens
-EffectLib
-EndlessEnchant
-Essentials
-EssentialsAntiBuild
-EssentialsChat
-EssentialsProtect
-EssentialsSpawn
-KHG Abilities
-Magic (3.0-RC1)
-McMMO
-MobArena
-Sentry
-NoDrop
-SimpleBack-1.5
-SimpleItemIds
-SpeedBoots
-UnbreakableEquip
-Vault
-WorldEdit

 

@lwkreeper Not sure what plugin is causing it... Maybe 'NoDrop'? But try removing plugins that it might be and re-add them when you confirm it's not that plugin. Then Tahg me if you find it.