Highend: Gray Area After Header

I recently uploaded Highend and I have this gray area on single posts. It was once on the main blog page but it has since been fixed. I can’t figure out what could be causing it. I inspected the element and it says it has something to do with a slider. Is that true? Here is the link:

http://www.teacherrevolutions.com/traditional-grade-book-programs-fail/