I had the same problem, but I went digging around on here. I found a guy who hit his earpiece with a shot of canned air, said he hasn't had problems since. I tried it over 4 weeks ago (2 days after I had the phone) and it does work. No problems since.
I just got this new X a few days ago and no way in heck was I going to put up with a buzzing speaker. Right off the thing was horrible and I thought I would have to return it.
I did a search and saw the compressed air idea. I was skeptical but got my compressor out when I got home.