I use the Magic Trackpad on my MP3,1 and lately (probably since upgrading to Mavericks) it is driving my nuts. When I start up my Mac Pro it quickly gets to the login screen, but here it easily sits for 15 seconds before recognising and connecting my Magic Trackpad. It connects and I have no further problems at all. I have tried deleting the references to the Trackpad in the Bluetooth setup, and the Trackpad is the only BT peripheral I am using, but alas, it still takes a long time next time I reboot. Anyone?