I'm another that will say, it drives me bananas!! I love the mouse otherwise, but it's just way too touchy, and when attempting to just move around on the map, it instead ends up zooming way in our out, many times when just moving the mouse across the web page to get to another button, textbox etc.
I know there's a few other examples where this happens, but I can't think iof it right off. Will report back next time I encounter it.
It does seem most sensitive with Google Maps than anything else; Via Safari, or Firefox/opera etc.
Be nice if they resolve this, so I can stop yelling obscenities when getting driving directions. 8)