Gaps between regions with Upfront Theme

Suddenly, gaps are showing up between regions on the home page of this site. Searching through support documents, I found two lines of CSS to add, but they didn't work.
(.upfront-region-container-main .upfront-region-container-bg {padding-bottom:0px})
and
(.upfront-region-container-main .upfront-region-container-bg {padding-bottom:0px!important;})

The poster (a WPMU Dev Admin) also suggested "re-creating extended access," but I have no idea what that means, and I can't find it anywhere.