Using 3d transformations screws up on non-WebKits

``` javascript
$(".box").css({ y: 200, rotateX: 30 }).transit({ y: 0 });
```

This will fail in Firefox (FF9/Mac) because it tries to use `rotateX`, which isn't supported in Firefox yet. The actual result is that `translate` will be stuck on `translate(0,200px)`.
