Your arena rating calc on this site says "updated for 2.2" but in fact is not. It's updated, but not correctly is my guess. It does not match up with the blizzard calc available at the armory. Now while normally I would believe anyone BUT bliz, in measuring points and figuring out F'ed up calculations, I'll go with them having the right formula.
No big deal, just thought you would like to know, and I didn't see it posted anywhere else.
A delayed thanks for this site, I use it often, love it much, and /dance in joy every time i visit.