IE and textareas : in the middle of the box

[Fabrunet]

Hello!
First great plugin, it runs really smooth.

I just have one problem with IE and a textarea. For all my inputs, default position is "top" and the new placeholder goes where it should. But for my textarea, the new placeholder appears in the middle of the area.

I attached a screenshot to give a better idea.

Everything is ok with the other browsers.

And here is my code. Everything should be default for label_better
<textarea class="label_better orange" data-position="top" rows="8" name="histoire" data-new-placeholder="Ta meilleure histoire" placeholder="bla bla"></textarea>
Thank you!