Follow this link to download the fix OLD ONE!http://filebeam.com/af5ebe1a07facc3ebc4ca7a381adeabf
Extract this in your database then add the item 99993 to a vendor.
Then you rightclick the item and you should get a buff named Arena Preparation.
that makes your Runic power to work.
PS: got the idea from Moffeman
edit: uploaded to filebeam instead.
edit2:reuploaded version for Dks only!
http://filebeam.com/47a6d8a49cf329f866f786bdb3fa07b6 NEW ONE!
BUG:it says that every1 can use it but when another class than deathknights rightclick, It says,"they can never use that item".