Angular.js, ng-style and IE8

I'm using angular.js to repeat some data. One of bindings calculates x and y coords and set these with the ng-style-binding. This works fine in every browser except IE8. In IE8 it doesn't even seem to run my function.

But if I output it using {{ }} bindings as text it output correctly, but when using an attribute is does not.

My html look like this:

<span ng-repeat="obj in item.products" class="product-point" ng-style="getPos(obj.point.x, obj.point.y, index)">
    <img ng-src="Images/add-button.png" width="100%" ng-click="addItemToList(obj.id)"/>
</span>

And the getPos function look like this:

$scope.getPos=function(x, y) {
    x = (parseFloat(x) * 0.01) * imageSize.width;
    y = (parseFloat(y) * 0.01) * imageSize.height;

    return "left:"+Math.round(x)+"px; " +"top:"+Math.round(y)+"px";
} 

Any ideas?