I think I figured out why I was seeing what appeared to be "Mod Trolling" on my posts.
Due my good Karma, my posts are being visualized with a default +2 score points, as someone else had modded me +1 (underrated).
However, I must confess that I know that half my posts doesn't deserve a +1 mod (being it real or just karma biased), and I did noticed that a good part of my modded down posts was being modded as "-1 Overrated".
Well, if I even think that that posts didn't deserve a +2 score, what can be said from some random moderator? :-)
So, the Mod Trolling problem doesn't appears to be so bad as I thought. These "-1 Overrated" mods I was getting are due some mediocre posts being listed with a "+1 Excellent Karma" being added automatically,
(Ok, perhaps this should be obvious and ululant to me - - but I thought a good idea to share anyway)