Video picture chopped off when scrolling

Hi. I try to put a video (youtube) on a page in SharePoint 2013 or SharePoint Online. It works fine. However, when I use the scrollbar to scroll down the page, the image from the video breaks. This is only a problem when I use IE 8. Can anyone tell me how I can avoid this problem? 

Thanks in advance,

Kim

Note: I use the same code on a page in SharePoint 2007 and it is ok when using IE 8.