Banner roll up on scroll down no longer works

Hi. First of all I should say that the upgrade to 11.x from 10.1 went very smoothly for us. We just had a couple of items and some formatting to work. Here's the second item that we cannot figure out. We have site banners that are in the body part of the header layout. On 10.1 prior to the upgrade that body area of the header layout would roll up and disappear as one scrolled down the page. This meant if you had a banner graphic it would roll up and disappear as the content scrolled up. That doesn't work anymore. Instead the banner or whatever other content in the body section of the header layout stays put. Is there a work around for this? Thanks.