It does register threads that you have responded to, but the only thing the OP is doing wrong is expecting this site to be usable. One is unable to find anything in one's profile under ANY tab as the ordering of the Qs and As is so erratic. If they are prepared to invest the amount of programming needed in all 5 one should be ordered by OP, one by last answer, one by one's own last answer, and so on.
If you only need 4, that is, JJ. Otherwise what's the point of that sidebar? It's never updated by time of last answer, which is the only thing that would be any use, and either only very erratically updated by time of last subscription or has actually been fixed in that respect since I last looked.
I know what you mean mallam, it is a bit pointless. I think the time relates to the when the thread was started and doesn't tell you when you added it or when any new post are added, so in other words 'useless' really.