Griffon in Northend Can't use?!

Why can't I use my Griffon in Northend? I bought all three of the of them I can't still use it. It says, you can't use that here. But I have used it in Outlands without a problem. Got my training in Outlands and bought 2 Grif but still it won't work. I think it's a bug of some sort or am I missing something?

Buy cold weather flying?

http://www.wowhead.com/spell=54197/cold-weather-flying
"Cold Weather Flying requires at least 225 skill in Riding and grants you the ability to use a flying mount (epic or non-epic) in Northrend. It can be trained at level 68 from any Flying Trainer at a cost of 500. This is a passive ability, and will not replace your existing flying skill, so you will still need to pay the full cost if you wish to train Artisan Riding."

Not yet. Hahaha alright, I'll look for it later. Thanks Widdin!