Players have discovered that a Shaman Talent actually increases damage taken rather than decreases damage taken.
Earlier today, Ortemist-Zul'Jin and Bondd-Illidan discovered that the general class talent Ancestral Defense is bugged.
Until this talent is fixed, AoE abilities will deal slightly more damage to Shamans. Be careful!
This talent has been around since 10.0.5, when it was changed from:
to the current value of:
Some players speculate that when the talent when converted from Avoidance to AoE damage reduction, the sign wasn't correctly changed from a positive to a minus, since Avoidance required a positive value.