Problem with Scatter Plots under Firefox (Chrome & IE ok)

Hi,

I've just encountered a problem which seems specific to Firefox (everything works fine with Chrome or IE). Here's a test on fiddle: http://jsfiddle.net/xaakLz5a/3/

The scatter plot is embedded in a div and the div is positioned thanks to a css transform:

```
#container {
top: 50%;
left: 50%;
position: absolute;
transform: translateY(-50%) translateX(-50%);
-webkit-transform: translateY(-50%) translateX(-50%);
height: 480px;
}
```

With Firefox, pointing a data point with the mouse doesn't work. It seems the problem is related to "wrong" mouse coordinates returned by d3.mouse(this). Firefox seems to return coordinates without taking into account the css transform.

I think the diagnostic is sound but I don't know how to fix the problem reliably.

Thanks in advance !
laurent