Do countless rounds of MF on Eldritch with 400 MF zon and get crap.
Do ONE round with no MF javazon and Eldritch coughs up 3-socket Head Hunters Glory, Spike Thorn, and Eschuta Temper orb.
Becoming more and more convinced MF has nothing to do with gear or charms but is just random. Maybe some little under fed and under paid weasel at Blizzard turns a switch on every now and then for MF.