I have a shadow priest which reached level 70 a couple of months ago. In Sethekk Halls for example where there are those shaman mobs, and in ZA at Halazzi a few days ago, I noticed that my Mind Flay does not work against the totems, I cant remember if I get an "Immune" notice, but the MF just does not connect. Is this a known something that I have somehow missed? havent tried others spells on it, usually by the time my dots tick on it or I finish casting MB the other people have killed the totem already.