Please dont take me wrong i know about you , this i was telling because first time i have saw this problem. of post counting wrongly showing in my profile. I know that you check everyone's posting history and then counting it. I am following you for past more then 2 yrs when i joined this forum.
I read that mods are purging useless/repetitive threads along with their responses. If a thread you had responded to gets deleted you don't get a notification.
That's correct, moderation is cracking down (to a certain point, at least more than before) on the spam problem, which included the trashing/deletion of a bunch of threads.
Which also means there is no problem and posts are not showing up wrongly.
Similar situation of changed profile post counts have occured several times in the past already, when theymos issued global post recounts for example.