chrome/opera anchor shift away after adding dom elements

[UaeDarling]

Say I have a URL: http://rythmengine.org/doc/user_manual.md#commentImmediately after the page is loaded, the anchor is shown correctly, however I have a script to automatically add some iframes across the page, chrome/opera will later on shift away from the anchor \[code\]#comment\[/code\], firefox and IE (10) are all good. Any idea how to fix it in Chrome/opera?