maybe these mobs got some brawler abilities?
monks are able to remove effects like stuns and mez from themselves for example.
if it happens while fighting group encounter there would also be the possiblity that one of the mobs can "cure" the mez.
just some ideas, why it must not be a bug in any case.
and PigLick is right, all spells are usually supposed to hold their full duration once they land on a mob.
edit: ha, Gilbertus beat me by a second...
Message Edited by zitha on 10-19-2005 09:58 AM