Hmm...have you taken an extended break from KHI at all during your time here?
If so, then your older posts might have been deleted along with the old, inactive thread that they were in, and there is nothing that can be done, unfortunately.
If not, then I'm afraid that this is most likely an error and you will have to contact one of the administrators.
I apologize if I wasn't of very much help to you, and I wish you luck in getting this resolved.