Horizontal movement of site design while loading banner

If I insert google banners into the simpleads blocks and set the google ads loaded asynchron then at chrome browser it leads to a flackering because of horizontal site movement.

First the page is loaded. As the banner is loaded later asynchron the page html "middle" caclculates the position without this additional block. After few milisecounds the banner is loaded and the position of the page is realigned again. This leads to flackering of website. This could be prevented by allocation the block size from the beginning.