Mongoose Recipe Drop from Moroes

So I was wondering on Icecrown,

Mongoose enchants already exist ( I have one on my staff ), but when I'm running through Karazkhan and killing Moroes with another player who has 450 enchanting (which should guarantee 100% drop rate), the recipe doesn't seem to drop at all!

I tried Group Loot, Free for All, Master Loot, and it never showed up. I've been trying for the past 3 weeks and nothing.

I was wondering if there were any enchanters who have the mongoose enchant to tell me if they had this sort of issue? I've put in a bug tracker report but I don't think it will move forward any time soon.

I noticed that with TBC they had this problem so I don't know if the updated content for TBC was put into WOTLK so that it bugged it?