The way the bonus from Imp. zerker stance is calculated, is not correct. The 10% is applied for all AP you have, not only the AP from items. (Don't know exactly for unleashed rage as we dont have an ench shammy, but I guess its the same).
So cell H156 instead of
[top]H147*H150*H151+H153 should be
(H147+H153)*H150*H151
Cheers.