Unhappily, this zooming problem due to involuntary "pinching", which already happened to me with Safari 3, is much worse on Safari 4. The Zoom in/out feature in S4 is by some buggy reason much faster and it is quite hard to set the right zoom to the desired setting by pinching.
Yes, I also had a black MacBook with a separate button, and yes, I use a lot my thumb for clicking. I can retrain myself to avoid thumb clicking, but it is hard to understand how there is not an option to turn off the feature in Safari preferences (as it happens in the finder, for example).
Last but not least, I tried Jeff Hawkins add-on (thanks a lot, Jeff) but it seems to not work on Safari 4. Unhappily, I did not tried it before on Safari 3, so I am not sure if this is a specific configuration problem on mine or a result of Safari 4. Anybody else noticed this? Thank in advance.
-- f mira