I'm having the exact same problem. Its weird because a single scroll "out" with the wheel has the opposite effect the first time and actually zooms in. Then it will zoom in and out, but in large stages, not gradual like used to. After zooming in the first time it will only let me then zoom out to half of the normal amount, like, it gets stuck more zoomed in than when it loaded up default. Hope there is a fix soon 🙂
