My Bridgestones (2008 X5) went at about the same miles as yours. I have a thread about it out there somewhere.

They got really noisy pretty quick once it started to happen. I was 2000 miles from home and we listened to the things for a few days.

As others have said, the Bridgestones are terrible tires. My 2010 X5 has them also, I'm just counting down the days until they are toast. Then again, I drove the new 550 Gran Turismo last night and it was awesome.