[nuzzle]

I had that problem with my diamond. I took it back and they just exchanged it. The problem was the magnet inside the phone broke off. Apparently it was just a dab of glue holding it on there. They told me that "forcing" the stylus in causes that, although I didnt force it ever.
It sounds like your magnet is knocked outta wack, which is causing the stylus to bang into it. Good luck man. I'd just take it back and replace it. I wasnt happy with my diamond and now I got the TP and loveeee it.