QUOTE
'double tap' with one finger it will zoom in or out
Have no idea what you're talking about. Nothing in "Mouse" on my setup concerns the Magic Pad, maybe on my wife's MBP. OTOH,
two-figner, double-tapping on the Pad acts exactly the same as it does on my iDevices: Zoom Out/In.

OTOH, there is a place in Trackpad for setting the "Secondary click", which can be defined in Mouse, I guess... Frankly, I had forgot about zooming with the two-finger, pinch/spread action, thanks for helping me start using that again, it's faster than command-+/- and is 'infinitely' variable.

OT(
third)H, there is a spot in Accessibility for Mouse and Trackpad settings. So, if you have stuff in the regular Mouse pref, it seems Apple has fallen, once again, into slapping things where ever the current favorite place might be for any particular day!
