said by Proteos
:Yea the bug is that you spec FFB (which doesn't include FM), but you have your second spec include FM (PVP frost, FB, Arcane, ect...) You go in that spec and cast your FM on the other mage in your raid (must have at least 2 mages for this to work) and he casts his on you. Then you can go back to your primary spec and your FM will still be on him as well as his on you. This only works if the other mage has FM in his primary spec (the one he is raiding with). So basically you take FFB spec which is not far off of the other specs as far as optimal dps and you add 6% extra crit to it...thus making it the best spec.
That was the bug I was talking about as well. It was fixed within like 2 weeks of being discovered.