I paired the magic mouse and keyboard from my iMac with my MacBook, now I can't use the built-in trackpad and keyboard anymore. I've tried deleting them from the Bluetooth preference pane but that doesn't fix the issue. I've used other bluetooth mice and keyboards with this MacBook before and not had this problem. My only thought is that possibly it's related to the fact that the peripherals came with the iMac and my MacBook now thinks that it's an iMac and doesn't have a built-in trackpad/keyboard.