Is this a vault related issue?

My log gets spammed with 20-100 lines/second.......Vault is the last thing to give an error before the spam starts. Ignore the MySQL error, this is on a test server without MySQL, the problem happens on the production server with MySQL working.

http://pastebin.com/ccRLyB1p

Full log: https://www.dropbox.com/s/se7zonf2lund90p/server.log?dl=0

Whatever version of Bukkit you're using is not official as it does not include SimpleJSON shaded in. You will need to get a version of bukkit that includes the simple json library.