If you are experiencing frequent disk I/O and your console is full of

25/08/12 4:30:19.506 PM ALSPlugin 235.55[62]: Failed to get brightness for displayID 0x042731c0

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I recently uninstalled all previous versions of xcode (I had all xcode from ios 3.2.x) to install 4.2 on my MBP. Although I freed around 30 GB, noticed an issue shortly. A process named BTServer is utilizing high CPU usage.