So my uBMBP mid 2009 has been making a faint buzzing noise in the left most corner of the base. I've only had it for about a month now, but whenever it's quiet, I can hear it. It sounds like the buzzing of an electrical current. It goes away when I unplug it from the adapter. So I decided to take it in for a check-up to see if there was maybe an issue. They had it for a few days and when I went to pick it up they said "we couldn't reproduce the issue." Are you kidding me? It's even louder now! I can hear it just sitting here, not even with my ear up to the computer. I think I'm going to take it back in, again, and insist upon showing them myself. You have to be deaf not to hear it, and it's driving me insane! I'm still way under warranty, so I'm hoping for an actual fix!