Problems positioning attachMovie mc's

Hi,

I was wondering if somebody could tell me what im doing wrong. I think the code speaks for it self:

 
per_row = 4; // Number of items per row
row_item = 0;
row_count = 0;
xmlNode = this.firstChild.childNodes[1];
total = xmlNode.childNodes.length; //length of xml file
for (i=0; i<total; i++) {
_root.dropZone.attachMovie("container", "pod"+i, i); //Duplicate the pod
row_item++;
_root.dropZone["pod"+i]._x += 180*row_item; //Give the new pod a new x value
_root.dropZone["pod"+i]._y += 215*row_count; //Give the new pod a new y value
if (row_item>=per_row) { //Check if we reached the maximum pods per row
row_item = 0;
row_count++;
}

And here you can find a screenshot of it: