Highcharts.js: how can stacked area graph animations be smooth?

I'm trying to make a realtime-updatin开发者_StackOverflowg stacked area graph in Highcharts.js. The problem is that the "area" of the graph disappears during .addPoint() animation.

I'm trying to achieve this effect: http://jsfiddle.net/DgKKX/5/

...But when I try it for area graphs, this happens: http://jsfiddle.net/DgKKX/6/

Anyone got a clue on how to make the "area" animate as well?

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Try duration and easing options of animation property similar to jsfiddle.net/DgKKX/5

Maybe you could also change area to 'areaspline' so that graph will be smooth