I've found a grab bag FAQ and I read this:

"Q: This question has to do with the proc on the scalars gloves artifact. Two questions, actually. As an enchanter, I have a self buff that ups my ABS by 10%. Evidently the buff that scalars gives is the same "type," because when it procs it overwrites my ABS buff. Is this on purpose? Second, my aug healer has a self dmg shield. When the scalars proc goes off, I guess the dmg shield and the 40% ABS buff are tied together, because it says I "already have this effect" and neither the dmg sheild nor the abs buff are put on me.

Please help me understand if this is correct, and if so, why?

A: Only one offensive proc and one defensive proc can be on a player at any given time. Bear in mind that being *able* to use an artifact does not necessarily mean the artifact is ideal for you. "

( http://camelotvault.ign.com/pagetools/p ... ews&id=240 )
It says that only 1 offensive and defensive proc can be on at same time, but it considers the self caster abs buff like proc, and healer dmg shield too :O
Anyone knows what this exactly means?