Cannot learn crippling poison

[WCChamp]

Hi, I'm a rogue level 20 trying to learn crippling poison. At first when I tried to learn it from the rogue trainer it was green but nothing happened when I clicked the Train button. Now it's greyed out, even though it says level 20 on it. The text says Requires: Level 20, Poisons(1) (the number '1' is in red).

Is this a bug or have I forgot to do something? I've restarted WoW without any effect.

Thanks for the help,
Cheers WCChamp

[dargus240]

Having the same problem I'm now lvl 26 and still can't get it.

Figured out the problem.

Go to Mathias shaw in sw pick up the quest he gives.