I've been using my trackpad on my unibody MBP for about a year now. I use the 'tap to click' setting, as I don't see a need to 'click' the pad when I can just tap it. However, today something very strange started happening - when I tap with one finger to do a single left click, it reacts as if I've done a middle click, activating the 'expose' function. Two finger tap still does right click, and my multi-finger swipes still activate their preset 'expose' functions, but single click has somehow broken.... Furthermore, adding to the 'weirdness', if I 'tap to click' on the left side of my trackpad, it works as it should, but anywhere towards the middle/right malfunctions as described above - I've looked to see if I've inadvertently ticked a function that causes it to work in this way, where a tap on the left, middle or right of the trackpad causes it to react as if it's doing a left, middle or right mouse click, but can't see anything.... Any ideas???!