What is happening:
If you have the same recipe several times, you can still consume it even though you have already learned how to craft the item the first time.
Encountered with the Front Leg Copper recipe I dropped in 4 copies from a floating tree in the Hearthlands.
What should be happening:
It shouldn't be possible to learn a recipe more than once.
Steps to reproduce the issue:
Get a recipe in several copy, and click on them.
Game client version:
Win 7 64bit