And the amounts of negative karma are so small that doesn't make much difference. I think forum need much more important things to fix and upgrade
Uh, man. I just noticed you're still at 2000 activity while I've reached 3000. Weird. 
I know you gave up thinking about it, but the difference is too big and I haven't written 1000 posts more than you.
ASk Lucius and Freemind, they know everything about it and are the specialists in activity frozen stuff.
I have seen users with way less karma than me who even joined later that have more activity than me.
I believe there is some bug, probably related to ad block (if it is a logged time issue, which I dont think it is, as the admin never confirmed it).
There is some random and secret stuff which may account is missing. It could be anything like sending 3 pm per day, or using alt tokens, or whatever.... I just gave up. This forum isn't transparent about the rules, which is not a good way to welcome members who are investing time in the forum.