The svirfneblin exterminator suit you can find in the low level salvage quest spawns magic eaters up to medium strength when you use the unique ability, it's treating the use as if you were casting a spell.
Here's a thread I made about this. Same scenario, I'm sure... (http://www.efupw.com/forums/forum/main-forums/bug-reports/88634-scavenged-svirfneblin-extermination-gear-damaged-magic-eaters)