It's working now with Maxthon 4.4.8.1000, Win 8.1.
It was not before. That's why I moved to the newest betas, up till 4.9.0.2800, along with some windows update, then my system started crashing. So, I just moved back to 4.4.8.1000, tried the zoom, and it works.
Not the compass/3D, though.
Amazing, isn't it??!!