starter quests (MagMell) mob kill doesn't count with self add damage and damage shield.

I've took the quest at Lieutenant Taellyn and killed few skeletal pawn (differents colors). After a few minutes i've return to her but no kill was counted on quest diary... I've took down the magical damage shield that someone casted on me and after few others monsters, only one kill was counted. So i also removed my self add damage and the next monster kill was given for my quest. So kills for quest doesn't work with self and return magical damage?