Game Mechanics: Feign death?

[Steelshine]

My feign death has recently been not working. I get no interrupt message, no falls to the ground message, and i'll be feigned, 30 seconds later some non-caster mobs will run up and kill me. There are no aoe's cast on me, I don't move. The chat log reads "you begin casting FD" then "you have gotten better at abjuration." then "x hits you for y. You died".