Embed google map is wrong displayed until resizing webpage

I too faced this issue, I solved it by triggering the Google maps resize event.

google.maps.event.trigger(map, 'resize');

Updates:

var map;
function initializeNewMap() {
 // add your code
  map = new google.maps.Map(document.getElementById("map_canvas"), myOptions); 
  google.maps.event.trigger(map, 'resize');
}

Hope you understand.